Recent studies suggest the rate of neoplasia in patients with complicated acute appendicitis initially managed nonoperatively is higher than previously reported.

This study aimed to determine the incidence and predictors of neoplasia in patients with complicated appendicitis treated nonoperatively.

We conducted a prospective cohort study of all patients who presented to a tertiary care center with acute appendicitis between 2019 and 2023. Patients with complicated appendicitis treated nonoperatively were included in the study cohort. Patient demographics, clinical course, radiological findings, and pathologic information were collected. The primary outcome was rate of neoplasia. Multivariable logistic regression analysis was performed to identify predictors of appendiceal neoplasia.

In total, we identified 1166 patients with acute appendicitis, of whom 75 patients had complicated appendicitis treated nonoperatively (median age 51 years [interquartile range 38-68]; 36 [48%] were female). Fifty-four (72%) patients had their appendix removed due to failure of nonoperative management, recurrent symptoms, suspicion of neoplasia, or elective surgery. The neoplasia rate among patients with complicated appendicitis initially treated nonoperatively was 16.0% (12/75). Two patients with neoplasia were younger than 40 years of age. Suspicion of malignancy on initial imaging was associated with an increased risk of appendiceal neoplasia (odds ratio 8.13, 95% confidence interval 1.20-55.15; p = 0.03). Age, sex, and appendiceal diameter were not significantly associated with appendiceal neoplasia.

The high rate of appendiceal neoplasia in patients with complicated appendicitis treated nonoperatively should be a factor in decision making for interval appendectomy for patients of all ages.

Non-Hodgkin lymphoma of the gastrointestinal tract is one of the least common primary malignancies, with diffuse large B-cell lymphoma being the most common histological subtype. Primary appendiceal lymphoma is extremely rare, with symptoms usually mimicking those of acute appendicitis. Here, we present a rare case of primary appendiceal non-Hodgkin lymphoma with ileocecal valve involvement and coexistence of Schistosoma eggs. The patient was initially diagnosed with acute perforation appendicitis. Following laparoscopic appendectomy, the patient developed an enterocutaneous fistula, which was addressed surgically after the failure of conservative management. Adjuvant chemotherapy with R-CHOP regimen was further planned for the patient.

Background: Immunohistochemistry (IHC) provides comprehensive information for morphology and pathologic characteristics and is a valuable tool for establishing the correct cancer diagnosis in clinical diagnostic pathology and determining prognosis. Objectives: The current study analyzes and compares the expression of Immunohistochemistry biomarkers on neuroendocrine and epithelial cell types of appendiceal neoplasms. Design: This systematic review adhered to the recommendations in the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. We performed a meta-analysis employing a random effects model with proportions to gauge the proportion of positive cases. Method: A comprehensive systematic search in PubMed, Web of Science, and Scopus databases was conducted based on the PRISMA statement up to August 2023. Studies reporting the immunohistochemistry biomarkers expression performed in patients with primary appendiceal neuroendocrine and epithelial cell neoplasms according to the most recent World Health Organization classification of malignant tumors were included. Results: Our systematic search included 56 observational articles that meet the eligibility criteria. Meta-analysis revealed an expression rate of 93%, 91%, 87%, 71%, 94%, 99%, 32%, 76%, 25%, and 91% for non-specific enolase (NSE), chromaffin A, synaptophysin, Serotonin, SATB2, Caudal-type homeobox 2 (CDX2), β-catenin, Carcinoembryonic antigen (CEA), Cytokeratin 7, and Cytokeratin 20, respectively. CDX2 and SATB2 were the most expressed markers. The expression rate had a significant association with tumor type. NSE and synaptophysin were the highest in neuroendocrine tumors, whereas CEA was more elevated in gablet cell carcinoids. Cytokeratin 20 is suitable for identifying epithelial cell neoplasms. Conclusion: The study indicates the proportion of positive cases in patients with primary neuroendocrine and epithelial cell appendiceal neoplasms.

National Comprehensive Cancer Network guidelines recommend segmental colectomy for appendiceal neuroendocrine neoplasms >2.0 cm given the risk for lymph node involvement. However, additional clinicopathologic factors are associated with nodal metastases, and thus survival. Given dynamic changes of prognosis over time, conditional overall survival, the probability of surviving after a specific interval, has emerged as a novel oncologic outcome, but is scarcely available for appendiceal neuroendocrine neoplasms.

Adults with stage I-III appendiceal neuroendocrine neoplasms who underwent colectomy from 2010-2017 were identified in the National Cancer Database. Tumor histologies included neuroendocrine tumor grade 1, neuroendocrine tumor grades 2 and 3, neuroendocrine carcinoma, mixed neuroendocrine non-neuroendocrine neoplasm, and goblet cell carcinoma.

Of 3,541 patients (median age 51 years, 43% male, 88% White), 16% had positive lymph nodes. Overall, 40% had neuroendocrine tumor grade 1, 4% neuroendocrine tumor grades 2 and 3, 10% neuroendocrine carcinoma, 12% mixed neuroendocrine non-neuroendocrine neoplasm, and 30% goblet cell carcinoma. Increasing depth of invasion, lymphovascular invasion, and increasing size were associated with lymph node metastases. Eighty-seven percent were alive at 2 years. Mortality after 2 years was associated with older age, mixed neuroendocrine non-neuroendocrine neoplasm and goblet cell carcinoma histology, penetration through serosa, nodal involvement, and tumor size.

In a national cohort, 1 in 6 patients had positive lymph nodes, which was associated with depth of invasion, lymphovascular invasion, and size. These findings indicate additional factors should be considered when determining the extent of surgical resection and surveillance to improve survival outcomes. Additionally, patients with penetration through serosa, and mixed neuroendocrine non-neuroendocrine neoplasm or goblet cell carcinoma histology had worse conditional overall survival, potentially reflecting more aggressive tumor biology that warrants closer follow-up.

Appendiceal mucinous neoplasms, including low-grade appendiceal mucinous neoplasms (LAMNs), are infrequent but clinically relevant due to their potential progression to pseudomyxoma peritonei. Timely diagnosis and surgical intervention are critical to preventing complications. We present a case series of three middle-aged men with LAMNs, each of whom exhibited right lower quadrant abdominal pain as their primary symptom. Diagnostic imaging in each case revealed features consistent with appendiceal mucoceles. Pathological findings confirmed LAMN, with varying extents of disease. One patient underwent an open appendectomy for LAMN confined to the appendix, while two required right hemicolectomy due to perforation and extra-appendiceal mucin involvement. LAMNs can be managed effectively through early detection and surgical resection. Complete resection with negative margins results in favorable outcomes and low recurrence rates. More aggressive treatments, including cytoreductive surgery with or without hyperthermic intraperitoneal chemotherapy, are necessary in cases with peritoneal involvement.

Peritoneal surface malignancies (PSMs) represent a biologically diverse group of cancers that range from primary peritoneal mesothelioma to metastatic gastrointestinal cancers. Because of the heterogenous nature of PSM, there is a large gap in molecular characterization of these cancers. This article reviews the underlying molecular and genetic mechanisms for PSM.

Gallium 68-DOTATATE positron emission tomography scanning is the cornerstone of nuclear medicine imaging for neuroendocrine tumours. Previous reports have demonstrated the potential for vertebral haemangiomata to mimic neuroendocrine skeletal metastases. We present the case of a 42-year-old man with a history of well-differentiated neuroendocrine tumour of the appendix, identified incidentally following emergency appendicectomy. Postoperative 68Ga-DOTATATE positron emission tomography/computed tomography scanning revealed an intensely gallium-avid retroperitoneal lesion adjacent to the right psoas muscle. Surgical excision of this lesion was recommended following multidisciplinary team discussion. Histological evaluation of the resected lesion revealed an intravascular capillary haemangioma. Haemangiomas can mimic residual or recurrent neuroendocrine tumour based on gallium avidity, and this should be considered in atypical cases.

Acute appendicitis is one of the most common causes of acute abdominal pain. Differences in the management of this large group of patients has important consequences for the patients and the healthcare system. Controversies regarding the understanding of the natural course of the disease, the utility of new diagnostic methods, and alternative treatments have lead to large variations in practice patterns between centres. These national guidelines present evidence-based recommendations aiming at a uniform, safe and cost-efficient management of this large group of patients.

A working group of six experts with broad clinical and research experience was formed. Additional expertise from outside was consulted during the process. A national survey revealed significant variations in the management of patients with suspicion of appendicitis. The evidence provided in published guidelines and reviews were extracted and systematically graded, according to the GRADE methodology. This was supplemented by additional more recent and more directed search of the literature. Patients treated for appendicitis were involved through interviews. The guidelines were reviewed by external experts before the final version was determined.

The guidelines cover an extensive number of issues: pathology, epidemiology, aetiology, natural history, clinical and laboratory diagnosis, diagnostic scoring systems, diagnostic imaging, treatment, nursing care, follow-up, quality registers and quality indicators, among others. Special considerations related to children and pregnant women are covered.

These national guidelines present an extensive and thorough review of the current knowledge base related to appendicitis, and provide up-to-date evidence-based recommendations for the management of this large group of patients.

Urothelial carcinoma of the urinary tract is the seventh most commonly diagnosed cancer in men and the 10th most common when both genders are considered. The most common site of malignancy in the urinary tract is the bladder. Radical cystectomy with urinary diversion is considered the best treatment option for patients with advanced urothelial bladder cancer. The most common long-term complication of urinary diversion is the deterioration of renal function, mainly caused by uretero-enteric strictures. Malignant neoplasms of the appendix are rare and metastatic involvement of the appendix during the course of any neoplastic disease is very rare. The current study presents a unique case of a 67-year-old man with urothelial cancer metastasis to the appendix, which was accidentally detected in an inflamed appendix removed during surgical treatment of an uretero-enteric stricture after radical cystectomy. To the best of our knowledge, bladder cancer metastasis to the appendix has not been previously reported as the first manifestation of dissemination. This case report provides evidence expanding the spectrum of known forms of metastatic urothelial carcinoma and may help in the development of guidelines for the surveillance and treatment of bladder cancer.

Peritoneal carcinomatosis is a common yet deadly manifestation of gastrointestinal cancers, with few effective treatments. To identify targetable determinants of peritoneal metastasis, we focused on appendiceal adenocarcinoma (AC), a gastrointestinal cancer that metastasizes almost exclusively to the peritoneum. Current treatments are extrapolated from colorectal cancer (CRC), yet AC has distinct genomic alterations, mucinous morphology and peritoneum restricted metastatic pattern. Further, no stable preclinical models of AC exist, limiting drug discovery and representing an unmet clinical need. We establish a first-in-class stable biobank of 16 long-term cultured AC patient-derived organoids (PDOs), including 3 matched, simultaneously resected primary AC-peritoneal carcinomatosis (AC-PC) pairs. By enriching for cancer cells, AC PDOs enable accurate genomic characterization relative to paucicellular AC tissue. We establish an organoid orthotopic intraperitoneal xenograft model that recapitulates diffuse peritoneal carcinomatosis and show that PC-organoids retain increased metastatic capacity, decreased growth factor dependency and sensitivity to standard of care chemotherapy relative to matched primary AC organoids. Single cell profiling of AC-PC pairs reveals dedifferentiation from mucinous differentiated states in primary AC into intestinal stem cell and fetal progenitor states in AC-PC, with upregulation of oncogenic signaling pathways. Through hypothesis-driven drug testing, we identify KRASMULTI-ON inhibitor RMC-7977 and Wnt-targeting tyrosine kinase inhibitor WNTinib as novel, clinically actionable strategies to target AC-PC more effectively.

Appendiceal epithelial tumors are rare and encompass a broad set of adenocarcinoma histologies, including mucinous (mAC), colonic-type (cAC), and goblet cell (GCA) adenocarcinomas. It has previously been reported that nodal disease predicted recurrence in patients with nonmetastatic appendiceal adenocarcinomas, supporting diagnostic laparoscopy with right hemicolectomy for staging and assessment for risk of recurrence. In this update, we sought to identify predictors of nodal disease on initial diagnostic pathology in nonmetastatic adenocarcinomas.

Patients with nonmetastatic appendiceal adenocarcinoma at a single institution from 1994 to 2020 were included. Clinicopathologic characteristics that predict recurrence and lymph node metastasis were analyzed. Workup included staging laparoscopy with right hemicolectomy, seriel imaging and biochemical monitoring.

A total of 147 patients with mAC (18%), cAC (22%), and GCAs (59%) were included. After median follow-up of 53 months, 23 (16%) patients recurred, most commonly in the peritoneal cavity (17/23, 74%). Recurrence rates were higher among node-positive patients (59% vs. 5%, P < 0.001). Nodal disease was more common in mAC (27%) and cAC (37%) than in GCA (11%); however, adenocarcinoma grade was not associated with nodal involvement.

Nodal metastasis was more common in mAC and cAC compared with GCA and was the only significant predictor of recurrence in appendix cancer.

Appendiceal carcinoma, a rare malignancy comprising less than 1% of gastrointestinal cancers, often presents diagnostic challenges due to its atypical symptoms. This report details a 68-year-old female with a history of severe anemia, gastrointestinal bleeding, and persistent abdominal symptoms, ultimately diagnosed with chronic small bowel obstruction caused by an appendiceal adenocarcinoma. Despite initial treatment for Helicobacter pylori-induced gastritis, her symptoms persisted, prompting further imaging that revealed a narrowed small bowel segment. Exploratory laparotomy uncovered a stricturing tumor 2 meters from the duodenojejunal junction, leading to en bloc resection of the tumor, appendix, and part of the lateral abdominal wall. Histopathology confirmed moderately differentiated adenocarcinoma. A multidisciplinary team recommended a complete right hemicolectomy, successfully performed despite extensive adhesions and a mesenteric abscess. Postoperatively, the patient recovered well, with ongoing management for anemia and close surveillance. This case highlights the importance of considering rare malignancies in differential diagnoses for chronic small bowel obstruction.

Mucinous adenocarcinoma of the appendix (MAA) is a rare primary malignancy with an incidence of 0.01-0.2% and often presents as acute appendicitis. We present a case of a 61-year-old male who initially presented with right iliac fossa pain, worsening over 3 days, accompanied by appetite loss but no other symptoms. The patient's history included a splenectomy and epilepsy. Physical examination and computed tomography scan suggested a picture of acute appendicitis. He underwent an emergency laparoscopic appendectomy that was converted to open right hemicolectomy due to the mass's adherence to the cecum. The mass, at the cecum, originating from the appendix, measured 10 × 7 × 7 cm. Pathology confirmed a moderately differentiated MAA. Accurate diagnosis requires a combination of imaging and histopathology. The patient recovered well and was discharged on Day 6 postoperatively. We aim to highlight the importance of distinguishing MAA from acute appendicitis and the need for careful preoperative evaluation.

Several neoplastic and non-neoplastic proliferations of the appendix can show varying degrees of serrated epithelial architecture. Of these, diffuse mucosal hyperplasia is most common, followed in frequency by low-grade mucinous and serrated neoplasms. It is important to distinguish serrated appendiceal neoplasms from their potential mimics because these entities may be managed differently. Diffuse mucosal hyperplasia is a non-neoplastic change that usually develops in the setting of resolving appendicitis and requires no further therapy or surveillance, and serrated neoplasms confined to the mucosa are adequately treated by appendectomy alone. On the other hand, low-grade appendiceal mucinous neoplasms may require surveillance, and those with extra-appendiceal spread differ from adenocarcinomas arising from serrated neoplasms with respect to both treatment and prognosis. Low-grade mucinous neoplasms in the peritoneum are frequently amenable to peritoneum-directed therapies alone, while adenocarcinomas derived from serrated neoplasms often spread to both regional lymph nodes and the peritoneum, potentially requiring right colectomy and systemic chemotherapy. The purpose of this review is to summarize the literature regarding the clinical and pathologic features of appendiceal lesions that show epithelial serration and provide the reader with helpful tips to distinguish serrated neoplasms from their mimics.

Appendiceal tumors are uncommon and, at times, discovered incidentally during histological examination. The histopathological classification of the disease is complex and has generated some controversy. The analysis of circulating tumor cells can be used for the early detection of metastatic potential. The aim of the present study was to examine the prognostic value of circulating tumor cells in patients with appendiceal tumors and peritoneal metastases. To our knowledge, this is the first study to examine CTCs in appendiceal tumors. We performed a prospective cohort study of consecutive patients treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy between 2015 and 2019 at a HIPEC referral center. In total, 31 patients were included in the analysis, and circulating tumor cells were detected in 15 patients (48%). CTC positivity was not associated with overall or recurrence-free survival, nor was it correlated with PCI score or histopathological grading. Surprisingly, however, CTCs were found in almost half the patients. The presence or quantities of these cells did not, on their own, predict systemic metastatic potential during the observed time, and they did not appear to significantly correlate with the oncological outcomes recorded.

Amyand's hernia is defined as the presence of the appendix within an inguinal hernia sac, which is often associated with appendicitis. The association of an Amyand's hernia with an appendicular tumor has been reported in very few cases. This case report presents a 67-year-old female patient who came to the emergency department with symptoms indicative of a complicated inguinal hernia. Following surgical treatment, the diagnosis of Amyand's hernia with cecal perforation associated with an appendicular tumor was established in the context of a previous laparoscopic femoral hernia repair. The combination of these conditions has not been previously reported. The presentation of this case provides data on the clinical presentation, diagnosis, and treatment of this rare pathology that requires a high clinical suspicion to achieve a preoperative diagnosis.

Appendicectomy is the most frequently performed emergency general surgical procedure. Previous research has highlighted discrepancies between initial intraoperative laparoscopic diagnoses and subsequent histopathology reports following appendicectomy. In the United Kingdom (UK), routine histopathological examination is the established practice, ensuring precise diagnosis of appendiceal specimens. This retrospective analysis aims to compare intraoperative laparoscopic assessments of the appendix with corresponding histopathology findings.

We conducted a retrospective analysis of 418 consecutive emergency laparoscopic appendectomies at Peterborough City Hospital in the UK between April 2018 and June 2019 for suspected appendicitis. Intraoperative findings were compared with histopathological examination outcomes using kappa statistics.

Of the 418 appendectomies analysed, we found a substantial agreement between surgeons and pathologists (kappa = 0.71, P < 0.001) in detecting overall abnormalities of appendices. This agreement was also high for detecting inflamed appendices (kappa = 0.72, P < 0.001). However, of the six neoplastic lesions confirmed in the pathologists' final report, only two were suspected during laparoscopy.

While laparoscopic assessments of the appendix demonstrate a statistically significant and improved agreement with histopathological findings in detecting abnormal and inflamed appendices, the ability of surgeons to identify neoplasia appears suboptimal based on our small sample of neoplasia cases. The data strongly support the continued practice of routine histopathological examination following appendicectomy due to its crucial role in avoiding missed diagnoses and ensuring better patient outcomes.

Despite the rarity of appendiceal tumors, research in this field has intensified, resulting in a growing number of studies and published papers. Surprisingly, no comprehensive bibliometric analysis has specifically addressed appendiceal tumors.

To offer a thorough analysis of the current landscape and future trends in appendiceal tumor research.

In our bibliometric analysis studies, we explored the Web of Science Core Collection database. The bibliographic details of the chosen publications were automatically converted and analyzed using the bibliometric package in the R environment. Additionally, we employed VoSviewer to create cooperation network maps for countries, institutions, and authors, as well as clustering maps for keywords. Furthermore, CiteSpace, another software tool, was utilized to build dual-map overlays of journals and analyze references with citation bursts.

Our study included 780 English-language articles published after 2010. The number of related publications and citations has increased in the past decade. The United States leads in this area, but there is a need to improve cooperation and communication among countries and institutions. Co-occurrence analysis also revealed close collaboration among different authors. Annals of Surgical Oncology was the most influential journal in this field. Analysis of references with high co-citations and references with citation bursts, consistent with analysis of keywords and hotspots, indicated that current research primarily centers on the classification and management of appendiceal mucinous neoplasms and consequent pseudomyxoma peritonei. Despite the abundance of clinical studies, a greater number of in-depth basic research studies should be conducted.

Current research on appendiceal tumors focuses on classification and management of appendiceal mucinous neoplasms and pseudomyxoma peritonei. Enhanced collaboration and basic research are vital for further advancement.

Breast cancer is considered one of the most common cancers worldwide. The most common sites for breast cancer to metastasize are the lymph nodes, bones, lungs, brain, and liver. Involvement of the gastrointestinal tract is uncommon, and metastasis to the appendix is rare. We report a case involving a 43-year-old woman with no previous history of malignancy who presented with acute appendicitis and underwent laparoscopic appendectomy, with the final histopathological assessment revealing metastatic breast cancer.

Nonoperative management of uncomplicated appendicitis is currently being promoted as treatment option, albeit 0.7-2.5% of appendectomies performed due to suspected acute appendicitis show histologically malignant findings. The purpose of this study was to investigate the incidence of neoplasm and malignancy of the appendix in patients presenting with suspected acute appendicitis in real world setting.

This is a retrospective single-centre investigation of 457 patients undergoing appendectomy between the years 2017-2020. The patients' demographics, symptoms and diagnosis, intraoperative findings, and histopathological results were analysed.

In 3.7% (n = 17) histological analysis revealed neoplasms or malignancies. Median age was 48 years (20-90 years), without sex predominance. Leukocytes (11.3 ± 3.7 G/l) and C-reactive protein (54.2 ± 69.0 mg/l) were elevated. Histological analysis revealed low-grade mucinous appendiceal neoplasia (n = 3), sessile serrated adenoma of the appendix (n = 3), neuroendocrine tumours (n = 7), appendiceal adenocarcinoma of intestinal type (n = 3), and goblet cell carcinoma (n = 1). Additional treatment varied between no treatment or follow-up due to early tumour stage (n = 4), follow-up care (n = 3), additional surgical treatment (n = 8), or best supportive care (n = 2).

Preoperative diagnosis of appendiceal tumours is difficult. Nonoperative management of patients with acute, uncomplicated appendicitis potentially prevents the correct diagnosis of malignant appendiceal pathologies. Therefore, close follow-up or surgical removal of the appendix is mandatory.

We investigated the impact of the COVID-19 pandemic on trends of presentation, management and pathology findings in patients who underwent an appendicectomy for suspected acute appendicitis.

The retrospective study reviewed patients (n = 939 adults and n = 329 children) who had an appendicectomy performed for suspected acute appendicitis and histopathology assessment in the Belfast Health and Social Care Trust, Northern Ireland. Pre-COVID-19 (March 2019 to February 2020) and COVID-19 Year 1 (March 2020 to February 2021) data were compared. Chi-squared tests were applied to compare timeframes.

513 adult appendicectomies were performed in the immediate year pre-COVID-19, compared to 426 in COVID-19 Year 1, representing a 17% reduction. No such reduction was seen within the paediatric population, likely related to a change in regional paediatric referral criteria during the pandemic. When comparing COVID-19 Year 1 with pre-pandemic, fewer patients presented with <24 hours of symptoms (45% v 53%, p = 0.005), and there was greater use of pre-operative computed tomography imaging in adults (63.2% v 48.7%, p<0.001). Fewer adult and paediatric cases of simple acute appendicitis and non-diagnostic specimens, with relative increased proportions of perforated acute appendicitis, were observed in COVID-19 Year 1 compared with pre-pandemic. No absolute increase in perforated acute appendicitis cases was observed in adults.

Year 1 of the COVID-19 pandemic was associated with delayed presentation of acute appendicitis in adults and children. In adults, an overall reduction in appendicectomy operations, increased use of pre-operative diagnostic imaging, and fewer specimens showing simple acute appendicitis or non-diagnostic features, collectively support appropriate restriction of surgery for those patients with a more certain acute appendicitis diagnosis.

Appendiceal metastases of breast cancer (BC) are very rare, and there are few reports of resection. Asymptomatic appendiceal enlargement is often suspected to be a primary appendiceal tumor, making it difficult to suspect metastatic tumors, especially metastases from BC. On the other hand, advances in drug therapy, including hormonal therapy for BC, have prolonged survival, and there is a possibility of encountering metastatic cases that have rarely been seen before. We herein present a case in which an enlarged appendix, identified during hormonal therapy for advanced BC, was laparoscopically removed and diagnosed as BC metastasis. A 53-year-old woman had been diagnosed with invasive ductal carcinoma (IDC) based on a breast biopsy, and the appendiceal specimen was diagnosed as invasive lobular carcinoma (ILC). We herein report this unique case and provide a detailed review of 13 previous reports.

Voltage gated calcium channels (VGCCs) play a critical role in neural transmission. Antibodies that target these ion channels can disrupt cellular signal transmission resulting in various clinical presentations. VGCC antibodies are most commonly associated with paraneoplastic syndromes such as Lambert-Eatons myasthenic syndrome. Here, we report a 47-year-old female with Stage IV appendiceal adenocarcinoma status post appendectomy and right hemicolectomy, who presented with progressive memory impairment, aphasia, ataxia, weakness, and headache. Neurologic exam was notable for right-sided parietal drift, decreased right arm swing, and ataxia of the bilateral upper extremities, more prominent on the right side. MRI of the brain with and without contrast was unremarkable. Cerebrospinal fluid (CSF) was notable for an elevated myelin basic protein (4.9 ng/mL, normal reference 0.0-3.7 ng/mL) with normal cell count, flow cytometry, and cytology. An extensive serum autoimmune neurology antibody evaluation revealed elevated VGCC autoantibodies (observed value: 96.1 pmol/L, normal range 0.0-30.0 pmol/L). A diagnosis of paraneoplastic voltage gated calcium channel antibodies secondary to appendiceal adenocarcinoma was made. The patient was treated with five exchanges with plasmapheresis over 10 days with significant clinical improvement in her symptoms. Upon literature review, this would be the first reported case of VGCC antibodies associated with appendiceal adenocarcinoma.

Acute appendicitis resulting from inflammation of the mucosa is the most common cause of emergency surgical causes. However, acute appendicitis caused by metastasis from other organs is very rare. Patients having this entity were only described in the literature as case reports. This study aims to analyze data from published articles about this condition.

We performed a systematic review using the PRISMA protocol. PubMed/MEDLINE, Embase and the Google Scholar Library were searched up to the end of December 2022.

A total of 34 patients were included, of which 22 were male. The mean age was 58.94. Primary site of tumors were mainly lungs (32.35%), breast (20.59%), and stomach (17.65%). All patients underwent surgical treatment except one patient who was given medical treatment. In 10 patients (29.41%), acute appendicitis was the initial manifestation to diagnose the primary malignancy and in 21 patients (61.77%), there were other sites of secondary lesions. Post operative mortality was reported in 1 patient (2.93%).

Acute appendicitis secondary to metastatic disease is uncommon but rarely will be the presenting sign of new cancer diagnosis. Most of the patients have other sites of secondary lesions. Surgical treatment is commonly performed to treat appendicitis.

Appendicitis is one of the most common causes of abdominal surgery emergencies worldwide. Here, we report a case of acute appendicitis as a primary presentation of gastric adenocarcinoma with appendiceal metastasis and no evidence of other lesions. This case can be added to only a few other reported cases, showing a similar situation that can help clarify the spread of gastric adenocarcinoma.

Due to the scarcity of low-grade appendiceal mucinous neoplasm (LAMN), there is an absence of systematized guidelines concerning its management, especially after incidental finding on an appendiceal specimen. In this study, we evaluate the active surveillance (AS) strategy adopted for a series of patients diagnosed with LAMN on resection specimens who were considered to have a low risk of pseudomyxoma progression.

Thirty patients were included between April 2014 and July 2021, with a female majority and a median follow-up period of 3.1 years. The inclusion criteria were as follows: LAMN diagnosis on appendiceal specimens, confirmed in an expert center, limited extra-appendiceal mucin resected and localized around the appendix, normal biology (CEA, CA199, CA125) and normal abdominopelvic MRI. AS included physical exam (trocar scar), biology and MRI, 6 months postoperatively, then yearly for 10 years.

As an initial surgery, 77 % had an appendectomy as their initial intervention, 17 % had a cecectomy, and 6 % had a right colectomy. After follow-up, 87 % of patients showed no sign of disease progression by MRI, while 13 % progressed to PMP. MRI performed in the first postoperative year predicted the disease prognosis in 97 % of patients.

The AS strategy, based on MRI, is a valid option after incidental LAMN diagnosis.

The risk-benefit balance of prophylactic appendectomy in patients undergoing left colorectal cancer resection is unclear. The aim of this report is to assess the proportion of histologically abnormal appendices in patients undergoing colorectal cancer resection in a unit where standard of care is appendectomy, with consent, when left-sided resection is performed.

A retrospective study on a prospectively collected database was conducted in a single tertiary-care center. Overall, 717 consecutive patients undergoing colorectal cancer resection between January 2015 and June 2021 were analyzed. The primary outcome was the proportion of histologically abnormal appendix specimens at prophylactic appendectomy. The secondary outcome was complications from prophylactic appendectomy.

Overall, 576/717 (80%) patients had appendectomy at colorectal cancer surgery. In total, 234/576 (41%) had a right-/extended-right hemicolectomy or subtotal colectomy which incorporates appendectomy, and 342/576 (59%) had left-sided resection (left-hemicolectomy, anterior resection or abdominoperineal excision) with prophylactic appendectomy. At definitive histology, 534/576 (92.7%) had a normal appendix. The remaining 42/576 (7.3%) showed abnormal findings, including: 14/576 (2.4%) inflammatory appendix pathology, 2/576 (0.3%) endometriosis, 8/576 (1.4%) hyperplastic polyp, and 18/576 (3.1%) appendix tumors, which encompassed six low-grade appendiceal mucinous neoplasms (LAMNs), three carcinoids, and nine serrated polyps. In the 342 patients who had prophylactic appendectomy, 10 (2.9%) had a neoplasm (two LAMN, three carcinoids, and five serrated polyps). There were no complications attributable to appendectomy.

Occult appendix pathology in patients undergoing colorectal cancer resection is uncommon when prophylactic appendectomy was performed. However, approximately 3% of patients had a synchronous appendix neoplasm.

The purpose of this study was to explore the appropriate surgical procedure and clinical decision for appendiceal adenocarcinoma.

A total of 1,984 appendiceal adenocarcinoma patients from 2004 to 2015 were retrospectively identified from the Surveillance, Epidemiology, and End Results (SEER) database. All patients were divided into three groups based on the extent of surgical resection: appendectomy (N = 335), partial colectomy (N = 390) and right hemicolectomy (N = 1,259). The clinicopathological features and survival outcomes of three groups were compared, and independent prognostic factors were assessed.

The 5-year OS rates of patients who underwent appendectomy, partial colectomy and right hemicolectomy were 58.3%, 65.5% and 69.1%, respectively (right hemicolectomy vs appendectomy, P < 0.001; right hemicolectomy vs partial colectomy, P = 0.285; partial colectomy vs appendectomy, P = 0.045). The 5-year CSS rates of patients who underwent appendectomy, partial colectomy and right hemicolectomy were 73.2%, 77.0% and 78.7%, respectively (right hemicolectomy vs appendectomy, P = 0.046; right hemicolectomy vs partial colectomy, P = 0.545; partial colectomy vs appendectomy, P = 0.246). The subgroup analysis based on the pathological TNM stage indicated that there was no survival difference amongst three surgical procedures for stage I patients (5-year CSS rate: 90.8%, 93.9% and 98.1%, respectively). The prognosis of patients who underwent an appendectomy was poorer than that of those who underwent partial colectomy (5-year OS rate: 53.5% vs 67.1%, P = 0.005; 5-year CSS rate: 65.2% vs 78.7%, P = 0.003) or right hemicolectomy (5-year OS rate: 74.2% vs 53.23%, P < 0.001; 5-year CSS rate: 65.2% vs 82.5%, P < 0.001) for stage II disease. Right hemicolectomy did not show a survival advantage over partial colectomy for stage II (5-year CSS, P = 0.255) and stage III (5-year CSS, P = 0.846) appendiceal adenocarcinoma.

Right hemicolectomy may not always be necessary for appendiceal adenocarcinoma patients. An appendectomy could be sufficient for therapeutic effect of stage I patients, but limited for stage II patients. Right hemicolectomy was not superior to partial colectomy for advanced stage patients, suggesting omission of standard hemicolectomy might be feasible. However, adequate lymphadenectomy should be strongly recommended.

Risk of malignant tumors increase with age;hence, careful examination of older patients should be consdiered when identifying the causes of acute appendicitis. Here, we report a case of a patient with cecum cancer with synchronous metastases to the small intestine that was found during acute appendicitis.

A 74-year-old man presented with right lower abdominal pain. Physical examination revealed deep tenderness at McBurney's point. Enhanced computed tomography scan showed an abscess around the enlarged appendix and a thickened cecum wall. Colonoscopy revealed a type 2 tumor in the ileocecal region, and pathological examination of the biopsied specimen revealed adenocarcinoma. Microscopic findings revealed two type 2 tumors in the small intestine, pathologically diagnosed as cecum cancer metastases. The final diagnosis was acute appendicitis caused by cecum cancer with synchronous metastases to the small intestine, pStage ⅣB pT4bN1aM1b. The patient received adjuvant chemotherapy and has currently been disease-free for 24 months.

In prolonged appendicitis among older adults, the possibility of malignancy should be considered during preoperative examination and prior to selecting a treatment plan. Delays in the diagnosis of colorectal cancer and metastases may lead to missed opportunities for complete resection and poor prognosis. J. Med. Invest. 71 : 293-297, August, 2024.

This manuscript discusses a rare case of acute appendicitis caused by metastasis from invasive breast carcinoma of no special type in a 70-year-old female previously diagnosed with breast cancer. It delves into the diagnostic challenges and management complexities of such unusual clinical presentations. The paper includes an analysis of 19 documented cases, enriching the understanding of metastatic patterns and treatment strategies in breast cancer. It underlines the importance of considering a history of malignancy when diagnosing acute abdominal conditions and emphasizes a comprehensive approach in interpreting diagnostic imaging in patients with past oncological issues to effectively manage metastatic breast cancer exhibiting atypical manifestations.

The standard for cancer staging in the United States for all cancer sites, including primary carcinomas of the appendix, is the American Joint Committee on Cancer (AJCC) staging system. AJCC staging criteria undergo periodic revisions, led by a panel of site-specific experts, to maintain contemporary staging definitions through the evaluation of new evidence. Since its last revision, the AJCC has restructured its processes to include prospectively collected data because large data sets have become increasingly robust and available over time. Thus survival analyses using AJCC eighth edition staging criteria were used to inform stage group revisions in the version 9 AJCC staging system, including appendiceal cancer. Although the current AJCC staging definitions were maintained for appendiceal cancer, incorporating survival analysis into the version 9 staging system provided unique insight into the clinical challenges in staging rare malignancies. This article highlights the critical clinical components of the now published version 9 AJCC staging system for appendix cancer, which (1) justified the separation of three different histologies (non-mucinous, mucinous, signet-ring cell) in terms of prognostic variance, (2) demonstrated the clinical implications and challenges in staging heterogeneous and rare tumors, and (3) emphasized the influence of data limitations on survival analysis for low-grade appendiceal mucinous neoplasms.

The aim of this retrospective cohort study was to describe the findings on histopathological examination of removed, macroscopically non-diseased, vermicular appendix during another primary surgical procedure (incidental appendectomy (IA)). Previous studies disapproved IA but were based on the possibility of complicated appendicitis. We observed the prevalence of neoplasms of the appendix in IA versus the appendectomy performed due to acute appendicitis (AA).

The database of histopathology reports of the Surgery Department, University Hospital of Split was reviewed in the period from January 1, 2017, to December 31, 2021. A total of 2832 histopathology reports were reviewed.

There was no difference in gender distribution between these two groups, but AA had a statistically significantly lower median patient age compared to the group IA (40 vs. 68 years; P < 0.001). In the AA group, there were 84.5% acute appendicitis, 11.1% normal appendiceal reports, 3.2% appendiceal neoplasms, and 1.2% other pathologies. The group IA had 89.5% normal findings of the appendix, 7.2% appendiceal neoplasms, and 0.5% other pathology. The difference in neoplasm prevalence between IA and AA groups was 4.0% (95%CI: 2.2 to 5.8), P < 0.001. The number of incidental appendectomies needed to detect one neoplasm of the appendix is 25.

Incidental appendectomies in patients undergoing abdominal surgery revealed a relatively high prevalence of appendiceal neoplasms above the age of 60 years. Prospective studies about incidental appendectomies, their clinical consequences, and impact on prognosis should be performed to define the value of incidental appendectomy in those patients.

Appendiceal neuroendocrine tumours (aNETs) are rare neoplasms of the gastrointestinal tract often diagnosed incidentally at the time of appendicectomy. Appendicectomy is considered curative in the majority of cases but guidelines recommend right-sided hemicolectomy (RHC) for those with specific high-risk features despite no data supporting a survival benefit. We performed a retrospective search of multi-disciplinary tumour board and pathology databases from 2012 to 2022 to identify cases of aNET treated at our centre. Follow-up data were obtained from the electronic healthcare records. A total of 142 cases of aNET were included for analysis. Mean age at presentation was 34, of which 76% were female and 92% of aNETs were located in the tip/middle of the appendix; 90% were grade 1, and 93% had R0 resection. Tumour size was <1 cm in 54%, 1-2 cm in 36%, >2 cm in 9%. A total of 43 patients (30%) underwent RHC with lymph node metastases identified in 16 (37%). Lymph node metastases were associated with tumour size >2 cm (p = .008) and higher tumour grade (p = .041) on multivariate analysis. For aNET 1-2 cm, lymph node metastases were identified in 7/22 who had RHC (32%) with tumour grade the only significant risk factor (p = .046). Distant metastases were identified in 2 cases (1%), diagnosed synchronously and associated with grade 2 tumours. Overall survival for those with lymph node metastases was 100% after a median 4 years. Progression-free survival was 93%, with a single case of disease progression associated with synchronous distant metastases at initial diagnosis. Lymph node metastases in aNET are associated with higher tumour grade and tumour size >2 cm. Disease progression in the setting of lymph node metastases is rare. The significance of lymph node metastases and need for completion RHC remains uncertain.

Few reports have described a submucosal tumor (SMT)-like colon tumor together with appendiceal cancer. Moreover, some appendiceal tumors may exhibit a cecal protuberance. Here, we report an uncommon case of appendiceal cancer with an SMT-like tumor, which was a protuberant lesion in the ascending colon. To our knowledge, this is the first report in Japan. Our case was a 50-year-old man with an ascending colon tumor presented at our hospital for further evaluation of this lesion. This was discovered as a cystic lesion near the ascending colon on colonoscopy. Our initial diagnosis was an ascending colon SMT-like tumor, and our treatment strategy was laparoscopic resection. The differential diagnosis was appendiceal cancer or mucocele. Postoperative pathological findings led to a diagnosis of adenocarcinoma of the appendix. The postoperative course was uneventful, and the patient was followed up with computed tomography and blood sampling on an outpatient basis.

This meta-analysis aimed to compare the efficacy and safety of antibiotic treatment and appendectomy for acute uncomplicated appendicitis.

We searched the randomized controlled studies (RCTs) comparing appendectomy with antibiotic treatment for uncomplicated acute appendicitis in the electronic database including Pubmed, Embase, Cochrane, Web of Science, CNKI, VIP, and WanFang. The primary outcomes included complication-free treatment success at 1 year, complications, surgical complications, and the complicated appendicitis rates. Secondary outcomes included negative appendicitis, length of hospital stay, the quality of life at 1 month, and the impact of an appendicolith on antibiotic therapy.

Twelve randomized controlled studies were included. Compared with surgery group, the antibiotic group decreased the complication-free treatment success at 1 year (RR 0.81; 95% CI 0.73-0.91; z = 3.65; p = 0.000). Statistically significance was existed between antibiotic group and surgical group with both surgical types(open and laparoscopic) (RR 0.43; 95% CI 0.31-0.58; z = 5.36; p = 0.000), while no between the antibiotic treatment and laparoscopic surgery (RR 0.72; 95% CI 0.41-1.24; z = 1.19; p = 0.236). There was no statistically significant differences between two groups of surgical complications (RR 1.38; 95% CI 0.70-2.73; z = 0.93; p = 0.353), the complicated appendicitis rate (RR 0.71; 95% CI 0.36-1.42; z = 0.96; p = 0.338), negative appendectomy rate (RR 1.11; 95% CI 0.69-1.79; z = 0.43; p = 0.670), duration of hospital stay (SMD 0.08; 95%CI -0.11-0.27; z = 0.80; p = 0.422), and quality of life at 1 month (SMD 0.09; 95%CI -0.03-0.20; z = 1.53; p = 0.127). However, in the antibiotic treatment group, appendicolith rates were statistically higher in those whose symptoms did not improve (RR 2.94; 95% CI 1.28-6.74; z = 2.55; p = 0.011).

Although the cure rate of antibiotics is lower than surgery, antibiotic treatment is still a reasonable option for patients with uncomplicated acute appendicitis who do not want surgery without having to worry about complications or complicating the original illness.

Neoplastic lesions of the vermiform appendix are still considered to be rare, some studies suggest that appendix cancer may be on the rise, with an estimated incidence of 0.08-0.1% of all appendiceal specimens. The lifetime incidence of malignant appendiceal tumors ranges from 0.2 to 0.5%.

Our study is applied at the Department of General Surgery at tertiary training and research hospital; 14 patients who had appendectomy or right hemicolectomy between December 2015 and April 2020 were evaluated.

The mean age of the patients was 52.3 ± 15.1 (range, 26-79) years. Gender of the patients were: five (35.7%) men and nine (64.3%) women. The clinical diagnosis was appendicitis without suspected findings in 11 (78.6%), appendicitis with suspected findings (appendiceal mass, etc.) in three (21.4%) of the patients, and there is no patient with asymptomatic or other rare findings. Surgeries applied for the patients were: nine (64.3%) underwent open appendectomy, four (28.6%) underwent laparoscopic appendectomy, and one (7.1%) underwent open right hemicolectomy. Histopathologic results were as follows: five (35.7%) neuroendocrine neoplasm, eight (57.1%), noninvasive mucinous neoplasm, and one (7.1%) adenocarcinoma.

While diagnosis and management of appendiceal pathology, surgeons should be familiar with suspected findings of appendiceal tumors and discuss them with patients to the possibility of histopathologic results.

This study investigated the clinicopathological characteristics and treatment of appendix neuroendocrine neoplasms in appendectomy specimens of our center.

The clinicopathological data, including age, sex, preoperative clinical manifestation, surgical method, and histopathological examination results of 11 patients with appendix neuroendocrine neoplasms confirmed by surgery and pathology between November 2005 and January 2023, were retrospectively analyzed.

In the histopathological examination of 7277 appendectomy specimens, 11 cases (0.2%) had appendix neuroendocrine neoplasms. Among the 11 patients, 8(72.7%) were males, and 3(27.3%) were females, with an average age of 48.1 years. All patients underwent emergency surgery. A total of 9 patients underwent open appendectomy, including 1 patient who underwent second-stage simple right hemicolectomy after an appendectomy, and two who underwent laparoscopic appendectomy. All 11 patients were followed up for a period of 1 to 17 years. All patients survived without any indication of tumor recurrence.

Appendiceal neuroendocrine neoplasms are low-grade malignant tumors originating from neuroendocrine cells. They are rarely seen in clinical practice and are often treated based on acute and chronic appendicitis symptoms. These tumors are challenging to diagnose before surgery due to the lack of specificity in clinical manifestations and auxiliary examinations. The diagnosis generally depends on postoperative pathology and immunohistochemistry. Despite the diagnostic challenges, these tumors have a favorable prognosis.

This report discusses the case of a 20-year-old female patient who presented with acute abdominal pain, nausea, and vomiting. Initial laboratory analyses suggested an inflammatory process, but imaging studies failed to reveal pathologies. The patient underwent a diagnostic laparoscopy, which showed a thickened and multicystic appendix with signs of acute inflammation. Pathology indicated a positive cytology for malignancy, with a grade 1 mixed well-differentiated neuroendocrine tumor (NET) and high-grade mucinous neoplasm identified in the middle and distal thirds of the appendix. Finding both tumors in the same patient is extremely rare and has been reported in a few cases. The case emphasizes the importance of considering appendiceal tumors in the differential diagnosis of acute abdominal pain, even in young patients, and highlights the value of laparoscopy in their diagnosis. The early detection and appropriate management of appendiceal tumors are crucial for improving patient outcomes.

Published data comparing peritoneal metastases from appendiceal cancers (pAC) and colorectal cancers (pCRC) remain sparse. We compared pAC and pCRC using comprehensive tumor profiling (CTP).

CTP was performed, including next-generation sequencing and analysis of copy number variation (CNV), microsatellite instability (MSI) and tumor mutational burden (TMB).

One hundred thirty-six pAC and 348 pCRC samples underwent CTP. The cohorts' age and gender were similar. pCRC demonstrated increased pathogenic variants (PATHs) in APC (48% vs. 3%, p < 0.01), ARID1A (12% vs. 2%, p < 0.01), BRAF (12% vs. 2%, p < 0.01), FBXW7 (7% vs. 2%, p < 0.01), KRAS (52% vs. 41%, p < 0.05), PIK3CA (15% vs. 2%, p < 0.01), and TP53 (53% vs. 23%, p < 0.01), and decreased PATHs in GNAS (8% vs. 31%, p < 0.01). There was no difference in CNV, fusion rate, or MSI. Median TMB was higher in pCRC (5.8 vs. 5.0 mutations per megabase, p = 0.0007). Rates of TMB-high tumors were similar (pAC 2.1% vs. pCRC 9.0%, p = 0.1957). pCRC had significantly more TMB-high tumors at lower thresholds.

Despite a reduced overall TMB, pAC demonstrated mutations distinct from those seen in pCRC. These may serve as discrete biomarkers for future study.

Appendiceal adenocarcinomas (ACs) are rare, histologically diverse malignancies treated as colorectal cancers despite having distinct biology and clinical behavior. To guide clinical decision making, we defined molecular subtypes of AC associated with patient survival, metastatic burden, and chemotherapy response.

A comprehensive molecular analysis was performed in patients with AC to define molecular subtypes. Associations between molecular subtype and overall survival, intraoperative peritoneal cancer index, and first-line chemotherapy response were assessed adjusting for histopathologic and clinical variables using multivariable Cox proportional hazards, linear regression, and logistic regression models.

We defined distinct molecular lineages of mucinous appendiceal adenocarcinoma (MAAP) from co-occurring mutations in GNAS, RAS, and TP53. Of 164 MAAP tumors, 24 were RAS-mutant (mut) predominant (RAS-mut/GNAS-wild-type [wt]/TP53-wt) with significantly decreased mutations and chromosomal alterations compared with tumors with GNAS mutations (GNAS-mut predominant) or TP53 mutations (TP53-mut predominant). No patient with RAS-mut predominant subtype metastatic MAAP died of cancer, and overall survival in this subgroup was significantly improved compared with patients with GNAS-mut (P = .05) and TP53-mut (P = .004) predominant subtypes. TP53-mut predominant subtypes were highly aneuploid; increased tumor aneuploidy was independently (P = .001) associated with poor prognosis. The findings retained significance in patients with any metastatic AC. RAS-mut predominant metastases exhibited reduced peritoneal tumor bulk (P = .04) and stromal invasion (P < .001) compared with GNAS-mut or TP53-mut predominant tumors, respectively. Patients with RAS-mut predominant MAAP responded more to first-line chemotherapy (50%) compared with patients with GNAS-mut predominant tumors (6%, P = .03).

AC molecular patterns identify distinct molecular subtypes: a clinically indolent RAS-mut/GNAS-wt/TP53-wt subtype; a chemotherapy-resistant GNAS-mut predominant subtype; and an aggressive, highly aneuploid TP53-mut predominant subtype. Each subtype exhibits conserved clinical behavior irrespective of histopathology.

A diagnostic and treatment strategy for appendiceal tumors (ATs) has not been established. We aimed to evaluate our treatment strategy in ATs, including laparoscopic surgery (LS), and to identify preoperative malignancy predictors.

A total of 51 patients between 2011 and 2021 were retrospectively reviewed. Data, including tumor markers and imaging findings, were compared between carcinoma and non-carcinoma patients. Validity of planned operation was evaluated based on pathological diagnosis.

Twenty-five patients were diagnosed with carcinoma, 13 with low-grade mucinous neoplasm, and 13 with other diseases. Symptoms were more commonly present in carcinoma patients than in non-carcinoma patients (68.0% vs. 23.1%, p = 0.001). Elevated CEA and CA19-9 were more frequently observed in carcinoma patients than in non-carcinoma patients (p < 0.01 and p = 0.04, respectively). Five carcinoma patients had malignancy on biopsy, compared with zero non-carcinoma patients. Significant differences were noted in the percentages of carcinoma and non-carcinoma patients with solid enhanced mass (41.7% vs. 0%, p < 0.001) and tumor wall irregularity (16.7% vs. 0%, p = 0.03) on imaging. Although the sensitivity was not high, the specificity and positive predictive value of these findings were 100%. Forty-two patients (82.4%) underwent LS as minimally invasive exploratory and/or radical operation, of whom 2 were converted to open surgery for invasion of adjacent organ. No patients had intraoperative complications or postoperative mortality.

Clinical symptoms, elevated tumor markers, and worrisome features of solid enhanced mass and tumor wall irregularity on imaging can be malignancy predictors. For management of ATs, LS is feasible and useful for diagnosis and treatment.