A number of weeks later the patient went on to have a rectal resection.
Rectal polyp
MACROSCOPIC DESCRIPTION
A mucosal resection with three orienting a long indicating proximal, a single indicating right distal and a double indicating left distal. The specimen measures proximal to distal 50 mm, left to right 45 mm. The mucosa contains a villous polypoid mass involving the entire surface. Right side inked green, left side inked blue. The tumour appears to extend to the proximal and distal resection margins.
MICROSCOPIC DESCRIPTION
Sections show colonic mucosa, submucosa and a small amount of muscularis propria, in which a tubulovillous adenoma is seen. The tumour comprises complex tubules and villous structures lined by columnar cells with reduced cytoplasmic mucin. The nuclei are stratified, with coarse chromatin. Some nuclei are vesicular with prominent nucleoli. Mitoses are seen close to the luminal surface. The muscularis mucosae is intact and there is no evidence of malignancy. The tumour appears completely excised in the planes of sections.
FINAL DIAGNOSIS
Tubulovillous adenoma with up to high grade dysplasia.