The rectal biopsy exhibits extensive active inflammatory ulceration and tissue devitalization, consistent with ischemic changes from external compression. The underlying stroma contains mostly crushed sheets of prominent, discohesive round cell infiltrate characterized by high N:C ratios, nuclear hyperchromasia, and pleomorphism. Picture is consistent with atypical large round cell infiltrate. Marker study (LCA, CD20, CK, HMB-45, NKX-3, SATB-2 & Synaptophysin) is recommended for definitive typing.
Rectal ulcers, mostly due to compression from cancer prostate.
Soft tissue fragments collectively measured 0.9 cm, totally embedded.
Rectal ulcers, Endoscopic Biopsy: