Ulcerated colonic mucosa infiltrated by a malignant tumor formed of irregular, crowded glands lined by stratified malignant columnar cells with lost mucigenic activity. Anaplasia and mitosis are moderate. Focal necrosis is observed. Separating stroma shows focal mild fibrosis with associated inflammatory reaction.
Rectal bleeding with abdominal pain. Colonoscopy revealed an ulcerative polypoid colonic mass 15 cm from the anal verge closing the lumen. CT scan revealed thickening involving the distal part of the sigmoid with pericolic fat stranding.
Soft tissue fragments collectively measuring 1.2 x 1 x 1 cm, totally embedded.
Colonoscopic biopsy: