University of Texas Southwestern Medical Center Dallas, TX, United States
Award: Presidential Poster Award
Timothy A. Zaki, MD1, Mireille Mbah, MD1, Mariam Mir, MD2, Amin Amin, MD1, Shawn Shah, MD2 1University of Texas Southwestern Medical Center, Dallas, TX; 2Dallas VA Medical Center, Dallas, TX
Introduction: Colitis cystica profunda (CCP) is a rare benign lesion of the colon or rectum characterized by intramural mucous-containing cysts. While the etiology of CCP is unknown, knowledge of this benign entity is of clinical importance since its endoscopic, radiologic, and histologic features can mimic the appearance of mucous-secreting colorectal malignancies. Here, we describe a case of CCP in a middle-aged patient who presented with abdominal pain and diarrhea and found to have an incidental rectal lesion suspicious for CCP.
Case Description/Methods: A 58-year-old male with a history of chronic alcohol use presented with worsening nausea, vomiting, and non-bloody diarrhea for two weeks. He was afebrile with stable vital signs, and his physical exam was significant only for mild diffuse abdominal tenderness. Bloodwork was notable for an elevated lipase and mildly elevated transaminases. Stool studies were notable for an elevated lactoferrin, but negative bacterial and parasitic enteric pathogen panels. Abdominal CT and MRI imaging demonstrated pancreatic edema, diffuse colonic wall thickening, and a 4 x 3 centimeter submucosal cystic lesion in the distal rectum that did not appear to invade the muscularis propria. The patient’s pancreatitis and colitis resolved with fluids and antibiotics, and his cystic lesion was further characterized by flexible sigmoidoscopy (Figure 1A) and rectal ultrasound (Figure 1B). Cytopathology from fine needle biopsy revealed bland pools of extravasated extracellular mucin without any overt features of malignancy, suspicious for a diagnosis of CCP. However, there was no histopathologic evidence of any submucosa to provide certainty. Final histopathology (Figure 1C) was obtained after rectal examination under anesthesia with local resection of the mass, confirming the diagnosis of CCP.
Discussion: Our case highlights the importance of considering CCP, a benign condition, in the differential diagnosis of rectal masses that mimic malignancy. Although advanced imaging may aid in supporting the diagnosis, histopathology is required for definitive confirmation. Endoscopic biopsy often fails to obtain adequate tissue sampling to visualize the submucosa, creating diagnostic uncertainty that can be unsettling for physicians and patients alike. Definitive surgical resection removes the mass along with diagnostic uncertainty, but shared decision-making is needed prior to proceeding with a major surgical resection with associated morbidity and mortality for a benign cause.
Figure: Figure 1. (A) Flexible sigmoidoscopy showing a benign-appearing submucosal mass in the distal rectum; (B) endoscopic rectal ultrasound demonstrating a hypoechoic, bilobed submucosal lesion containing anechoic foci and surrounded by a hyperechoic rim, without involvement of the muscularis propria; (C) histopathology (hematoxylin and eosin staining) following resection of the rectal mass, revealing a mucin-filled cyst bordered by atrophic colonic mucosa and colonic mucinous epithelium, with evidence of surrounding fibrosis, without evidence of dysplasia or malignancy.
Disclosures: Timothy Zaki indicated no relevant financial relationships. Mireille Mbah indicated no relevant financial relationships. Mariam Mir indicated no relevant financial relationships. Amin Amin indicated no relevant financial relationships. Shawn Shah indicated no relevant financial relationships.
Timothy A. Zaki, MD1, Mireille Mbah, MD1, Mariam Mir, MD2, Amin Amin, MD1, Shawn Shah, MD2. P1235 - Colitis Cystica Profunda: A Rare Mimicker of Colorectal Neoplasia, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.