Presentation
Severe left lower abdominal pain with tenderness and leukocytosis.
Patient Data
Irregular circumferential wall thickening of the proximal sigmoid colon (length ~ 7 cm) with "apple core sign". A focal perforation of sigmoid wall with an adjacent extraluminal air-fluid collection showing a peripheral enhancement with extensive surrounding fat stranding and thickening with enhancement of the peritoneal reflections. Small perisigmoid and left common iliac lymphadenopathy.
Moderate intraperitoneal effusion with free peritoneal gas and extensive thickening of the peritoneal reflections (? peritonitis).
Thickening (9 mm) with the enhancement of the appendix, is most likely reactive.
Small left renal stone with cortical cyst as well as small umbilical hernia are noted (incidental findings).
Case Discussion
CT features of perforated sigmoid cancer with abscess formation and peritonitis that was confirmed at surgery. The tumor was pathologically proven to be adenocarcinoma.