P1216 - Incidental Detection of Extranodal Mantle Cell Lymphoma During Evaluation for Chronic Colitis Symptoms

Seyma Bayram, MD¹, Omar Alkasabrah, MD², Mehmet Talha Bayram, MD³, Mostafa Eysha, MD⁴, Vikas Khurana, MD¹
1The Wright Center for Graduate Medical Education, Scranton, PA; 2Landmark Medical Center, Woonsocket, RI; 3Geisinger Wyoming Valley Medical Center, Wilkes-Barre, PA; 4Texas Tech University Health Science Center El Paso, El Paso, TX

Introduction: Mantle cell lymphoma (MCL) is a rare subtype of non-Hodgkin lymphoma, accounting for approximately 3–7% of cases. While it mainly involves the lymph nodes, MCL can also affect extranodal sites such as the gastrointestinal (GI) tract, blood, and bone marrow. When the GI tract is involved, MCL may present with symptoms that mimic an inflammatory bowel disease (IBD) flare. We present an unusual case of extranodal MCL discovered incidentally during the evaluation of a patient with known ulcerative colitis (UC).

Case Description/

Methods: 77-year-old male with a 7 year history of ulcerative colitis (UC) controlled on mesalamine single treatment. He presented with complaints of persistent lower abdominal pain, rectal bleeding, and Diarrhea. On examination, he was afebrile with mild tenderness on palpation of the lower abdomen.
A contrast-enhanced CT of the abdomen and pelvis revealed interval development of retroperitoneal adenopathy suggestive of malignancy. A subsequent PET/CT scan showed hypermetabolic activity in both the retroperitoneal and mesenteric lymph nodes. There was also evidence of a distal sigmoid/rectal interface constriction, along with diffuse prostate involvement. Endoscopy and Colonoscopy was performed and Sigmoid colon biopsies were taken showing chronic active colitis with prominent lymphoid aggregates but no overt signs of malignancy. Immunohistochemical studies done on the biopsy samples revealed a diffuse, monomorphic lymphoid infiltration consistent with mantle cell lymphoma (MCL), expressing CD20+, CD5+, Cyclin D1+, and SOX-11+ markers, with a low Ki-67 proliferation index (10%). Genetic testing revealed p53 negativity, supporting the low-grade nature of the lymphoma. The lymphoma was confined to extranodal sites without evidence of systemic spread, and the staging indicated localized disease.
Given the indolent nature of the disease and the patient’s asymptomatic state at that time, a decision was made to initiate a “wait-and-watch” approach, with close follow-up and serial imaging.

Discussion: The GI tract is a common site of extranodal involvement in mantle cell lymphoma (MCL). While the colon is most frequently affected, MCL can involve any part of the GI tract. Endoscopically, the classic presentation is multiple lymphomatous polyposis. However, in our case, this characteristic finding was absent, indicating the diagnostic challenge in such presentations. Accurate diagnosis of MCL relies on histopathological evaluation and immunohistochemical staining.

Disclosures:
Seyma Bayram indicated no relevant financial relationships.
Omar Alkasabrah indicated no relevant financial relationships.
Mehmet Talha Bayram indicated no relevant financial relationships.
Mostafa Eysha indicated no relevant financial relationships.
Vikas Khurana indicated no relevant financial relationships.

Seyma Bayram, MD¹, Omar Alkasabrah, MD², Mehmet Talha Bayram, MD³, Mostafa Eysha, MD⁴, Vikas Khurana, MD¹. P1216 - Incidental Detection of Extranodal Mantle Cell Lymphoma During Evaluation for Chronic Colitis Symptoms, ACG 2025 Annual Scientific Meeting Abstracts. Phoenix, AZ: American College of Gastroenterology.