CLINICAL NOTES: 1. Rectal cancer Ultra low anterior resection 2. Distal Donut MACROSCOPIC DESCRIPTION: 1. "Rectum": A 275mm length anterior resection, diameter 20-30mm. The anterior peritoneal reflection is 30mm from distal margin. The posterior perirectal fat is non-peritonealised from 170mm from distal margin. There is up to 100mm mesocolon, up to 29mm posterior perirectal fat, up to 20mm anterior perirectal fat. Within the rectum, at the level of the anterior peritoneal reflection, (22mm from distal margin and 212mm from proximal margin), there is a pale brown smooth discoid tumour, 20x13x9mm. The tumour is causing a puckering of the underlying mucosa but appears to be limited to mucosa and submucosa, with intact muscularis propria. Tumour submitted in full. The tumour is on posterior wall of rectum, where there is up to 19mm of posterior perirectal fat (tumour is 30mm from posterior non-peritonealised surface). The distal 120mm of rectum shows diffuse polypoid lesions, 2-5mm maximum dimension (approximately 45 in total). The polyps are present at distal margin, and 155mm from proximal margin. The sigmoid mucosa contains a single 4mm diameter polyp,and is otherwise shiny and unremarkable. Representative sections of largest polyps submitted. Inking notation: proximal margin black, distal margin black, anterior circumferential margin blue, posterior circumferential margin green. BLOCK DESIGNATION: 1A - proximal margin. 1B - distal margin. 1C-1E - rectal tumour (submitted in full). 1F - largest rectal polyp bisected. 1G - four rectal polyps. 1H - seven whole nodes. 1I - six whole nodes. P9. 2. "Distal donut": A mucosal donut, 22x10mm, length 9mm. Staples removed. Longitudinal sections of mucosa submitted. P1. (CH) MICROSCOPIC DESCRIPTION: 1. The sections show invasive moderately differentiated adenocarcinoma arising in a tubulovillous adenoma with high grade dysplasia involving rectal mucosa. Tumour extends into the submucosa but does not appear to involve muscularis propria. No evidence of vascular, lymphatic or perineural invasion is seen. Of the five other polypoid lesions sampled, one is a sessile serrated adenoma and the remaining four are hyperplastic polyps. No evidence of metastatic tumour is seen in any of 10 lymph nodes. All resection margins are clear of tumour. 2. The section shows rectal mucosa and wall. A small hyperplastic polyp is noted within rectal mucosa. No evidence of invasive tumour is seen. DIAGNOSIS: 1. Rectum: Site - rectum. Type - moderately differentiated adenocarcinoma arising in tubulovillous adenoma with high grade dysplasia. Size - 20mm in maximum dimension. Local invasion - tumour extends through muscularis mucosae into submucosa; no evidence of involvement of muscularis propria seen. Lymphovascular invasion - absent. Perineural invasion - absent. Proximal, distal, radial - all clear of tumour. Lymph nodes - no evidence of metastatic tumour in any of 10 lymph nodes. Additional pathology - five sampled polypoid lesions - 1x sessile serrated adenoma; 4x hyperplastic polyp. AJCC (7th edition) Stage 1 (T1 N0 MX). *** Identification and sectioning of further lymph nodes pending Carnoy's treatment of perirectal fat. 2. Distal donut: Rectal mucosa with small hyperplastic polyp; no evidence of invasive tumour seen.