Colorectal Cancer Arising in a Diverticulum: Report of an Unusual Presentation.

Abstract

The coexistence of diverticulitis and colorectal cancer is rare but clinically significant. We present an unusual case of an elderly patient with recurrent acute diverticulitis, colonic obstruction due to a sigmoid stenosis, in which an adenocarcinoma originated within a diverticulum. This presentation is particularly challenging because the extramural growth pattern within the wall of the pseudodiverticulum, which lacks the muscularis propria layer, facilitates early transmural spread without a significant intraluminal mucosal mass, leading to an advanced diagnosis more frequently. This case underscores the need for high clinical vigilance and specialized radiologic review in patients with complex diverticular disease and unexplained stenosis.