Presentation
Long history of left lower quadrant pain. Change in bowel habit with increasing constipation. Biopsies are not conclusive of malignancy. Is there a colonic malignancy on imaging?
Patient Data
The large bowel is obstructed by a sigmoid colon stricture. There is circumferential thickening, with no diverticula in this segment, and the impression of shouldered edges at the proximal end of the stricture. Some adjacent peritoneal thickening is present. A few lymph nodes are seen in the vicinity but not particularly enlarged. This segment of the colon appears to be adherent to the left ovary. No adherence to other structures is identified. A small volume of free fluid is noted adjacent to the cecum. Air in the cecal wall is concerning for developing ischemia. No bowel perforation. No liver or lung abnormalities.
The lack of diverticula, relatively short stricture, and apparent shouldered edges makes this highly concerning for a malignant stricture.
HISTOLOGY REPORT
Clinical Details: Rectosigmoid mass.
Macroscopic: On opening, the mucosa shows no focal lesions. The muscle layer is thickened and diverticula are noted. There is a dense thickened area in the mesentery 30x25 mm. This is adjacent to the bowel wall. On slicing contains fat only. There was a separate piece of bowel 40 mm with no focal lesions.
Microscopic: The sigmoid colon shows crypt atrophy, architectural distortion and mucin depletion. The lamina propria is expanded with extensive chronic inflammation, areas of focally active inflammation and occasional crypt abscesses. There is prominent, diffuse lymphoid hyperplasia. The muscularis propria is hypertrophic and a diverticulum is noted. These features are consistent with diverticular disease. Seven lymph nodes were identified and show reactive changes only. There is no evidence of granulomas, dysplasia or malignancy.
Conclusion: Sigmoid colon - diverticular disease. No evidence of neoplasm.
Case Discussion
On the basis of the imaging findings of a lack of diverticula, a short stricture, and apparent shouldered edges, this was considered to be malignant, with an assumption that the biopsy findings were due to sampling error. This case highlights the overlap in findings between diverticular and malignant strictures of the sigmoid colon, with the pathology analysis here showing that this was in fact a diverticular stricture.
Contrast this with this case in which the imaging was suggestive of a diverticular stricture but post-operative pathology analysis identified an adenocarcinoma.