Anorectal gastrointestinal stromal tumors: a retrospective multicenter analysis of 15 cases emphasizing their high local recurrence rate and the need for standardized therapeutic approach.

PURPOSE: This study aims to report our multicenter experience with diagnosis, management, and prognosis of anorectal gastrointestinal stromal tumors (GIST). PATIENTS AND METHODS: We retrospectively reviewed cases treated and/or followed up at our institutions in the period 2000-2011. RESULTS: Fifteen patients were identified (eight men and seven women; mean age, 55 years). Presenting symptoms were rectal/perirectal (eight), rectovaginal space (four), or retrovesical/prostatic (three) mass. Primary surgical treatment was local excision (six), deep anterior resection (eight), and palliative diagnostic excision (one). Tumor mean size was 4.8 cm. All but two cases were high risk (Miettinen and Lasota, Semin Diagn Pathol 23:70-83, 2006). R0 resection was achieved in 46% of cases: one of six local excisions vs. five of seven deep anterior resection (16 vs. 71%, respectively). All three cases who received total mesorectal excision had R0. Non-R0 status was mainly due to opening of tumor capsule at surgery (Rx). Seven of 14 patients (50%) developed ≥1 pelvic local recurrences at a mean period of 48.4 months (mean follow-up, 61.6 months). Only two patients developed distant metastasis (adrenal, liver, and peritoneal). Recurrences developed after Rx (three), R1 (two), and unknown R-status (two). Successful mutational analysis in 13 patients revealed KIT mutations in all (10 exon 11, 2 exon 9, and 1 exon 13). CONCLUSION: Our results confirm the high local recurrence rate of anorectal GISTs (50%) which correlates with the common practice of suboptimal oncological primary tumor resection (Rx or R1 = 7/13). This uncommon subset of GISTs needs more standardized oncological surgical approach to minimize the propensity for local disease recurrence.

Neoadjuvant chemotherapy affects staging of colorectal liver metastasis--a comparison of PET, CT and intraoperative ultrasound.

PURPOSE: Surgery for colorectal liver metastasis facilitates long-term survival, and neoadjuvant chemotherapy improves resectability but may also alter staging accuracy. The aim of this study was to evaluate the effects of neoadjuvant chemotherapy on the efficacy of positron emission tomography (PET), PET-computed tomography (CT), CT and intraoperative ultrasound (IUS) in the detection of liver metastasis. METHODS: Between January 2007 and January 2010, 34 patients with resectable colorectal liver metastasis were included in this retrospective analysis. Seventeen patients had received neoadjuvant chemotherapy. PET or PET-CT, CT or magnetic resonance imaging (MRI) and IUS were performed in all patients. Sensitivity, specificity, positive predictive value and negative predictive value were analysed. Histopathological examination of the resected specimens served as standard reference. RESULTS: A total of 109 liver segments were resected, of which 50 showed no metastatic involvement (45.9%). For patients without systemic chemotherapy, sensitivities for PET, CT/MRI and IUS were 92%, 64% and 100% respectively as compared with 63%, 65% and 94% for patients after neoadjuvant chemotherapy in a segment-based analysis. For PET, standardised uptake values were decreased by 3.9 in 10 patients after chemotherapy whereas lesion diameters were similar (3.0 vs. 3.2 cm). Additional metastases were detected by IUS in seven patients resulting in a change of operative procedure in 20.6%. CONCLUSION: Staging accuracy of colorectal liver metastasis is influenced by neoadjuvant chemotherapy. For PET, decreased tumour metabolism rather than downsizing may account for a drop in sensitivity after neoadjuvant chemotherapy. IUS is critical to avoid incomplete resections.

Injecting methylene blue into the inferior mesenteric artery assures an adequate lymph node harvest and eliminates pathologist variability in nodal staging for rectal cancer.

PURPOSE: The American Joint Committee on Cancer recommends examination of a minimum of 12 lymph nodes in rectal cancer for accurate staging. Despite this, several studies have demonstrated that nodal harvest is highly variable and often inadequate. This study was designed to determine if staining the nodes with methylene blue dye produced a better and more accurate harvest in comparison with standard pathologic lymph node dissection. METHODS: Fifty patients with primary resectable rectal cancer were randomly assigned to undergo a standard nodal harvest or a harvest after ex vivo injection of the inferior mesenteric artery with methylene blue. A fat clearance technique was subsequently used to identify the maximum possible number of lymph nodes and metastasis. RESULTS: The average lymph node harvest was 30 +/- 13.5 in the stained group and 17 +/- 11 in the unstained group (P < 0.001). At least 12 nodes were identified in every case in the stained group. In the unstained group, 7 of 25 cases (28 percent) did not meet the minimum criteria of 12 nodes (P < 0.01). Among the pathologists for the stained group, no difference was found in the harvest (P < 0.05), but variability was detected between the pathologists in the unstained group (P = 0.6). After fat clearance, one case in the unstained group was upstaged, whereas no cases in the stained group were upstaged. CONCLUSIONS: Staining the lymph nodes with methylene blue dye is an accurate staging technique and reliably produces an adequate harvest.

Is There an Indication for Surgical Resection in Colorectal Adenoma?

BACKGROUND: Due to the adenoma-carcinoma sequence, complete removal of colorectal polyps is essential. METHOD: This article analyzes the role of surgery in the removal of colorectal adenoma. RESULTS: Nowadays, most adenomas are removed properly by endoscopic methods. Also in the resection of giant polyps and recurrent adenoma endoscopic data is convincing. Therefore, surgical resection of colorectal adenomas is required in the case of endoscopic inaccessibility. Reasons for this may be the location of the polyp, incomplete endoscopic resection, or suspected malignancy. Endoscopic or limited surgical resection of malignant adenomas is acceptable only if 'low-risk' criteria are fulfilled. Otherwise oncologic radical resection is recommended. In general, radical resection is also necessary in the case of polyps that are not suitable for endoscopic removal, because here the rate of colorectal carcinoma is high. CONCLUSION: If a surgical approach is necessary, minimally invasive surgery in the hands of an experienced laparoscopic surgeon is a suitable option. Adenomas in the lower two thirds of the rectum are suitable for transanal full-thickness resection. This is done by conventional resection or transanal endoscopic microsurgery. The histopathological preparation of these specimens provides diagnostic and therapeutic benefits, particularly compared to piecemeal resection of early carcinoma.