Colitis cystica profunda in a patient with ulcerative colitis: Case report and a brief review of the literature

Colitis cystica profunda (CCP) is an uncommon benign disease of the colorectum characterized by mucin-filled cystic glands in the submucosal and deeper layers of the intestinal wall. Its clinical, endoscopic, and radiological presentations are difficult to differentiate from colorectal cancer, particularly in patients suffering from inflammatory bowel disease. In this article, we report a 36-year-old man with an 8-year history of ulcerative colitis who was admitted with a history of intermittent rectal bleeding, mucoid discharge, tenesmus, and urgency for the last 6 months. A 4-cm ulcerated sessile mass at the rectosigmoid junction, suggestive of carcinoma, was demonstrated by colonoscopy. Cross-sectional imaging revealed focal rectal wall thickening, and pelvic MRI identified a submucosal lesion with multiple cystic spaces resulting in a characteristic ‘Swiss cheese’ appearance. Initial superficial biopsies were nondiagnostic. The endoscopic ultrasound-guided core biopsy demonstrated colonic glands displaced into the submucosa and muscularis propria, associated with smooth muscle proliferations and fibrosis, without cytologic atypia. Immunohistochemical (IHC) studies established a benign colonic epithelial origin, supporting the diagnosis of CCP. Based on the patient’s symptoms, size of the lesion, and suspicion of malignancy, the patient underwent laparoscopic low anterior resection with primary anastomosis. The final pathology confirmed the diagnosis of CCP with negative margins without dysplasia or malignancy. At 32 months of follow-up, the patient was symptom-free with no evidence of recurrence. This case emphasizes the need to consider CCP as a benign mimicker of colorectal cancer. It demonstrates the benefits of deep tissue sampling and multidisciplinary team review in achieving an accurate diagnosis and optimizing patient management.