Background: Transanal endoscopic microsurgery (TEM) is a minimally invasive approach for excising rectal polyps, particularly those with high-grade dysplasia (HGD) or early-stage rectal cancer (T1). This study aimed to evaluate the recurrence risk and its associated factors in patients treated with TEM for HGD and T1 rectal tumors. Methods: A retrospective review was conducted on 79 patients who underwent TEM for rectal lesions at Rabin Medical Center-Hasharon Hospital from 2005 to 2019. Data collected included demographics, tumor characteristics, and follow-up outcomes, with specific focus on tumor size, resection margins, mucin production, and distance from anal verge (AV). Separate and unified analyses were performed to assess the recurrence risk factors for both HGD and T1 patients. Results: Sixty-three patients were included in the final analysis. In the unified analysis, larger tumor size was significantly associated with increased recurrence risk (OR = 2.27, p = 0.028), and mucin production was a strong predictor of recurrence in the T1 group and combined analysis (p = 0.0012 and p = 0.014, respectively). Distance from AV demonstrated a borderline association with recurrence (p = 0.053). Conclusions: Larger tumor size and mucin production are significant predictors of recurrence in TEM-treated rectal polyps. Personalized follow-up and postoperative management are essential for patients with these risk factors to reduce the recurrence risk.

The most common technique for treating benign and early malignant rectal lesions is transanal endoscopic microsurgery (TEM). Local excision is an acceptable technique for high-risk and elderly patients, but there are hardly any data regarding young patients.

To describe TEM outcomes in patients under 50 years of age.

We collected demographic, clinical, and pathological data from all patients under the age of 50 years who underwent the TEM procedure at Hasharon Rabin Medical Center from January 2005 to December 2018.

During the study period, a total of 26 patients under the age of 50 years underwent TEM procedures. Their mean age was 43.3 years. Eleven (42.0%) were male. The mean operative time was 67 min, and the mean tumor size was 2.39 cm, with a mean anal verge distance of 8.50 cm. No major intraoperative or postoperative complications were recorded. The median length of stay was 2 d. Seven (26.9%) lesions were adenomas with low-grade dysplasia, four (15.4%) were high-grade dysplasia adenomas, two were T1 carcinomas (7.8%), and three were T2 carcinomas (11.5%). No residual disease was found following endoscopic polypectomy in two patients (7.8%), but four (15.4%) had other pathologies. Surgical margins were negative in all cases. Local recurrence was detected in one patient 33 mo following surgery.

Among young adult patients, TEM for benign rectal lesions has excellent outcomes. It may also offer a balance between the efficacy of complete oncologic resection and postoperative quality of life in the treatment of rectal cancer. In some cases, it may be considered an alternative to radical surgery.

Few studies on endoscopic resection (ER) for the treatment of non-gastric gastrointestinal (GI) stromal tumors (GISTs) have been conducted, and most have been case reports or case series. The aim of this study was to evaluate the effectiveness and safety of ER for non-gastric GISTs.

From January 2010 to December 2022, 329 patients who were diagnosed with GISTs underwent ER. After excluding 302 patients with gastric GISTs, we retrospectively assessed the data of 27 patients with non-gastric GISTs. The main outcome measures were en bloc resection, complete resection, residual disease, recurrence, and complications.

A total of 15(55.6%) females and 12(44.4%) males with a mean age of 53.8 ± 11.0 years were assessed. There were 19 (70.4%) GISTs in the esophagus, 2 (7.4%) in the duodenum, 3 (11.1%) in the colon and 3 (11.1%) in the rectum. The median tumor size was 12.0 mm (range 4.0-35.0 mm). Most of the GISTs (20, 74.1%) were very low risk, and the remaining 7(25.9%) were low risk. Both en bloc resection and complete resection were achieved in 25(92.6%) patients. Piecemeal resection mainly resulted from a larger tumor size, an irregular shape, and an extraluminal growth pattern. No residual disease or recurrence was noted during the follow-up period. The median operation time was 23 min (range 2-125 min). After excluding the operation time of EER, the operation time was prolonged to 37 min (range 12-125 min). Only one patient experienced mild abdominal pain, leading to a complication rate of 3.7%. No severe complications requiring for surgical interventions occurred.

ER was an effective and safe method for non-gastric GISTs in selected cases. GISTs of a small size and regular shape with an intraluminal growth pattern require complete resection.

Purpose: Rectal polyps with low-grade dysplasia (LGD) can be removed by local excision surgery (LE). It is unclear whether these lesions pose a higher risk for recurrence and cancer development and might warrant an early repeat rectal endoscopy. This study aims to assess the rectal cancer rate following local excision of LGD rectal lesions. Methods: A retrospective multicenter study including all patients that underwent LE for rectal polyps over a period of 11 years was conducted. Demographic, clinical, and surgical data of patients with LGD werecollected and analyzed. Results: Out of 274 patients that underwent LE of rectal lesions, 81 (30%) had a pathology of LGD. The mean patient age was 65 ± 11 years, and 52 (64%) were male. The mean distance from the anal verge was 7.2 ± 4.3 cm, and the average lesion was 3.2 ± 1.8 cm. Full thickness resection was achieved in 68 patients (84%), and four (5%) had involved margins for LGD. Nine patients (11%) had local recurrence and developed rectal cancer in an average time interval of 19.3 ± 14.5 months, with seven of them (78%) diagnosed less than two years after the initial LE. Seven of the nine patients were treated with another local excision, whilst one had a low anterior resection, and one was treated with radiation. The mean follow-up time was 25.3 ± 22.4 months. Conclusions: Locally resected rectal polyps with LGD may carry a significant risk of recurring and developing cancer within two years. This data suggests patients should have a closer surveillance protocol in place.

Very few data are available about the clinical relevance of magnetic resonance (MR) imaging in preoperative evaluation of rectal villous adenoma. The aim is to evaluate the impact of MR imaging for the surgical management of rectal villous adenoma treated by transanal endoscopic microsurgery (TEM).

All patients with histologically proven rectal villous tumours operated by TEM who had a preoperative MR imaging between 2009 and 2017 were retrospectively reviewed. All patients underwent TEM because preoperative evaluation suggested systematically usT0 or usT1 tumour. Pathological stage was blindly compared to preoperative MR imaging (location according to the anal verge and the peritoneal reflection, amount of circumferential involvement, tumour size and staging) and preoperative transrectal ultrasonography (TRUS) results.

Forty-five patients were included (24 men, mean age 65 ± 8 years) with TRUS data available only in 37. Pathologic results were pT0-pTis in 32, pT1 in 10 and pT2 in 3. TRUS diagnosed correctly 36/37 lesions (97%) and understaged one pT2 tumour. A significant correlation between TRUS and pathologic results was noted (r = 0.99; p = 0.01). MR imaging diagnosed correctly 19/42 pTis-T1 and 1/3 pT2 tumours (46%). Overstaging by MR imaging was noted in 25 cases (54%). No correlation between MR imaging and pathologic results was noted (r = 0.7; p = 0.3).

Preoperative evaluation of rectal villous adenoma is overstaged by MRI in more than half of the patients. This study suggests that the indication of local excision by TEM for rectal villous adenoma should be based on TRUS rather than on MRI.

The aim of this study is to assess postoperative morbidity and mortality in tumors with a proximal margin 15 cm or more from the anal verge operated with transanal endoscopic microsurgery (TEM).

This observational study of consecutive rectal tumor patients undergoing TEM was carried out from July 2004 to June 2017. We compared the results of rectal tumors at distances of ≥15 cm (group A) and <15 cm (group B) from the anal verge.

During the study period 667 patients were included: 118 in group A and 549 in group B. In the comparative analysis there were no significant differences in morbidity (p = 0.23), mortality (p = 0.32) or free margin involvement (p = 0.545). Differences were observed in terms of lesion size (p < 0.001), surgical time (p < 0.001) and peritoneal cavity perforation, which were all increased in group A.

TEM for lesions in the rectosigmoid junction is feasible and is not associated with higher morbidity or mortality.

Transanal endoscopic microsurgery (TEM) has been accepted worldwide for the treatment of local rectal lesions. Rare rectal tumors consist of several different types of malignant or benign tumors. Surgical management is considered to be the only curative option. The aim of this study is to investigate the role of TEM in the treatment of rare rectal tumors.

A total of 147 patients with rare rectal tumors underwent TEM in our center from April 2006 to May 2017. Clinical data were collected and a retrospective accurate database was constructed. Demographic characteristics, operative details, tumor details, complications, and follow-up data were analyzed.

Seventy-eight patients were male. Mean tumor diameter was 1.2 ± 0.7 cm and mean distance from the anal verge was 6.6 ± 2.3 cm. Full-thickness and complete resection with negative margins was achieved in all patients. Complications occurred in 3 patients during surgery and in 20 patients after surgery. Histopathologic results were neuroendocrine tumors in 104 patients; gastrointestinal stromal tumors in 35; melanoma, lymphoma, and leiomyoma each in 2; lipoma, and squamous carcinoma each in 1. One hundred thirty-five patients were followed up for 49.3 ± 33.2 months. Two patients died, 1 had local recurrence and 1 had a rectovaginal fistula 1 month after surgery. No local recurrence or metastasis, or fecal incontinence was observed in the remaining patients.

TEM is an optimal treatment option for selected rare rectal tumors. The complication rate is low and the therapeutic effect is satisfactory.

To assess the surgical outcome of transanal endoscopic surgery (TES) for rectal neoplasms in technically challenging indications.

All patients who underwent TES for a rectal neoplasm from 2007 to 2014 were included. Technically challenging indications included a tumour with (i) diameter ≥ 5 cm, (ii) involving ≥ 50% of the rectal circumference and (iii) located ≥ 10 cm from the anal verge. Patients were divided into three groups according to how many of these features they had, as follows: Group 1, none; Group 2, one; Group 3, two or more.

Of the 168 patients (80 benign and 88 malignant tumours) included in the study, 73 (44%) were in Group 1, 46 (27%) in Group 2 and 49 (29%) in Group 3. There was no difference between Group 1 and Group 2 with regard to peritoneal perforation (P = 0.210), severe postoperative morbidity (P = 0.804), length of hospital stay (P = 0.444), incomplete resection (P = 0.441), piecemeal resection (P = 0.740), locoregional recurrence (P = 0.307) and long-term symptomatic rectal stenosis (P = 0.076). Conversely Group 3 showed significantly impaired results compared with Group 1 with regard to peritoneal perforation (P = 0.003), piecemeal resection (P = 0.005), incomplete resection (P = 0.025), locoregional recurrence (P = 0.035) and long-term symptomatic rectal stenosis (P < 0.001), but no difference in severe postoperative morbidity (P = 0.328).

Transanal endoscopic surgery for rectal neoplasms appears to be safe and effective, even in patients presenting with a technically challenging tumours. Although the short- and long-term outcomes after TES are worse in patients with highly challenging tumours, nevertheless the technique should still be considered in patients at high risk of requiring a proctectomy.

Gastrointestinal stromal tumors (GISTs) are the most frequently diagnosed mesenchymal neoplasms of the gastrointestinal tract. Despite their biological and clinical heterogeneity, the majority of these tumors are positive for the receptor tyrosine kinase KIT and are driven by KIT- or platelet-derived growth factor receptor alpha (PDGFRA)-activating mutations. There are still uncertainties regarding their clinical and molecular characterization and the optimal treatment regimens, making it difficult to establish a universal treatment algorithm for these tumors.

From a clinical perspective, the main difference between GISTs and other gastrointestinal neoplasms is that the benign or malignant behavior of GISTs cannot be predicted from histopathology, but instead relies on empirically established scoring systems. Clinical data suggest that malignant potential may be an inherent quality of some GISTs rather than a feature acquired by the tumor during disease progression. Thus, some patients may require prolonged anti-tumor treatment even after complete surgical removal of the tumor.

Although GISTs are the most frequently occurring mesenchymal neoplasms in the gastrointestinal tract, no universal treatment algorithms exist. This paper reviews the current evidence that guides the management of GISTs.

The management of localized GISTs involves the use of surgical resection, with the inclusion of preoperative tyrosine kinase inhibitor treatment for locally advanced, primarily unresectable tumors and for resectable cases requiring extensive surgery. Imatinib is also indicated as adjuvant therapy after complete surgical removal of GISTs with a high estimated risk of recurrence unless specific mutations conferring imatinib resistance are present. The optimal duration of adjuvant treatment is still controversial. For patients with metastatic imatinib-sensitive GISTs, imatinib constitutes the first-line standard treatment. Molecular characterization of the tumor (with respect to the PDGFRA and KIT genes) is mandatory prior to imatinib therapy. Sunitinib and regorafenib are established as alternative treatments for patients demonstrating generalized disease progression on imatinib. New tyrosine kinase inhibitors such as ponatinib and crenolanib as well as drugs targeting alternative pathways are currently under investigation. Surgery and locally ablative treatments may be indicated in some metastatic patients.