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 mitoses are moderate. Focal necrosis is observed. Separating stroma shows focal mild fibrosis with associated inflammatory reaction.
Polypoidal mass 15 cm up to 25 cm from anal verge.
Soft tissue fragments collectively measured 1.2 cm, totally embedded.
Colonoscopic biopsy: