Presentation
History of Crohn disease. New onset of perianal pain and diarrhea. Imaging requested to rule out perianal abscess and fistula.
Patient Data
There is a semi-annular soft tissue mass involving the mid and lower rectum, extending over a length of 5 cm. The edges are the 12:00 and 9:00 positions. Abnormal soft tissue penetrates the muscularis propria into the mesorectal fat. The lesion extends to the top of the internal sphincters. There is no bulky mesorectal adenopathy and no changes of extramural venous invasion. The appearances are not typical for inflammatory bowel disease, with no perianal fistula or abscess, and are very suspicious for a malignancy.
Case Discussion
Subsequent investigations confirmed the presence of rectal adenocarcinoma.