There is marked circumferential bowel wall thickening extending from the anorectal junction to the distal sigmoid approximately 20 cm in length. The maximum wall thickness is 3cm noted at the distal sigmoid. There is no definitive rectal wall, mesorectal fat, urinary bladder or bone invasion.
This is a limited, unenhanced study but no evidence of metastatic disease is detected. No evidence of metastatic disease on unenhanced CT (not shown).
Conclusion: The appearance is consistent with an unusually large carpet-like rectal villous adenoma. Certainly an element of carcinoma may well co-exist.