While in children intussusception is often idiopathic, in adults it is commonly caused by a pathologic condition functioning as a lead point. It is important to note that a variety of pathologic conditions may trigger intussusception, with malignancy being a relatively frequent culprit in adults; this should be considered high on the differential diagnosis during evaluation.

This is a case of a 40-year-old female presenting to the emergency department (ED) with three days of acute on chronic, peri-umbilical abdominal pain described as waxing and waning, and pressure-like in nature. Initial computed tomography (CT) of the abdomen and pelvis with contrast in the ED (after her pain had resolved) re-demonstrated a previously noted 13 mm lesion in the gastric antrum but no clear cause of the pain. Endoscopic ultrasound was pursued, and the mass lesion was sampled via fine needle biopsy. Post-procedure the patient experienced another episode of severe pain which prompted a repeat stat CT abdomen and pelvis with contrast; this re-demonstrated the 13 mm antral lesion and in addition was remarkable for a gastro-gastric intussusception. An upper gastrointestinal gastrograffin series was ordered (completed only after the pain had subsided) and showed resolution of the intussusception. Histopathology was consistent with a diagnosis of low-grade neuroendocrine tumor (NET). Surgery was initially deferred during the hospitilization given the low grade pathology of the lesion; however further multidisciplinary discussion between Surgery, Oncology, and Gastroenterology recommended resection given the patient's recurrent abdominal pain with the NET functioning as a lead point for further intussusception, and the patient thus underwent robotically-assisted wedge resection.

We present a unique case of severe, intermittent, peri-umbilical pain related to gastro-gastric intussusception caused by an antral NET lead point. The case highlights the importance of considering neoplasms as the cause of intussusception in adults and the greater diagnostic yield when imaging is obtained while symptoms (in this case severe, episodic abdominal pain) are most apparent.

Appendiceal intussusception (AI) is a difficult disease to diagnose. Various features of the disease were analyzed in a 35-year-old female patient admitted with abdominal pain and diagnosed with AI. The diagnosis was made with colonoscopy and abdominal computed tomography. Laparoscopic partial cecum resection was performed. Pathology examination revealed foci of endometriosis externa, which infiltrated the muscular layer of the appendix. AI should be kept in mind in the differential diagnosis of recurrent abdominal pain. Colonoscopy is an indispensable examination for differential diagnosis. Laparoscopic partial cecum resection, preserving the ileocecal valve, is an appropriate treatment approach in irreducible cases that are not suspected to be malignant.

Intussusception of the appendix is a rare disease that constitutes a diagnostic challenge to the surgeon. The literature on this condition is limited to case reports. The demographics, presentation, and treatment remain debatable in the absence of a comprehensive review of the literature.

This article reports a case of a 40-year-old woman who presented with intussusception of the appendix caused by endometriosis. A comprehensive review of the English literature in PubMed was performed. The trends in incidence, sex predilection, presentation, and treatment of appendiceal intussusception were derived based on the reports of 191 patients.

The incidence was more common in adults (76%) than in children (24%). Female patients (72%) were 2 times more affected in adults than in children, whereas male patients (58%) seem to be more affected in the pediatric population. Intussusception of the appendix has most commonly a chronic presentation (63%). Endometriosis (33%) and inflammation (76%) were the most common pathologic findings in adults and children, respectively. Only 49% of patients were treated by simple appendectomy; 49% patients underwent partial colectomy; and 2% of patients had their appendixes endoscopically removed.

Intussusception of the appendix is a rare condition. Most cases are diagnosed during operation of the patients suspected to have appendicitis. In this report we present a seventy one year-old man with a history of periumbilical intermittent abdominal pain for several months. None of the paraclinical tests were useful for determining the diagnosis. Colonoscopy performed during the last episode of abdominal pain revealed the prolapsed appendix in the cecum and the patient was sent to the operating room. Macroscopic appearance of the appendix was normal and microscopic examination revealed follicular hyperplasia and acute focal appendicitis. Appendiceal intussusception should be considered in differential diagnosis of intermittent abdominal pain and colonoscopic diagnosis could be very important to avoid dangerous or unnecessary decision making.

Primary appendiceal neoplasms are a rare clinical and pathological entity. We report a case of synchronous appendiceal tumours of different histological types which presented as a symptomatic palpable and radiologically apparent mass in the right iliac fossa. This case demonstrates the importance of pre-operative diagnosis of these neoplasms, as it may alter the surgical approach and obviate the need for additional surgery. Furthermore, some of the controversies associated with the management of an appendix mass in the elderly population are discussed.