EP497 - A Rare Mantle Cell Lymphoma of The Colon and Rectum in a 65-Year-Old Female with Diffuse Lymphadenopathy

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Purpose/Background: Mantle cell lymphoma (MCL) is an aggressive, sporadic, rare sub-type of B-cell non-Hodgkin lymphoma (NHL), comprising 5 percent of all non-Hodgkin lymphomas. Although MCL predominantly presents with an aggressive clinical course, an indolent leukemia variant of MCL, as well as multiple morphological variants that mimic other lymphoid neoplasms, have also been recognized. Historically, MCL is three times more common in men and has a median diagnostic age in the 6th and 7th decade of life. Colon and rectum involvement is rare in primary GI tract lymphomas, and primary gastrointestinal tract MCL comprises only 2% of primary GI lymphomas. Early diagnosis and treatment are crucial due to the aggressive nature of this malignancy.

Methods/Interventions: A 65-year-old female with history of hepatitis and chronic treatment-resistant depression who presented to the ER with lower back pain, loss of appetite, hot flashes, and night sweats ongoing for the past month. She had a screening colonoscopy 4 years prior her presentation which revealed one benign polyp that was removed at the time. The patient reported 23-pack year smoking history. CT abdomen and pelvis demonstrated an abnormal appearance of the cecal tip and appendix. Concern was raised for a neoplastic process given the appearance of clustered enlarged right lower quadrant mesenteric lymph nodes as well as bilateral inguinal nodes and multiple enlarged lymph nodes throughout the abdomen. The patient was discharged from the ER with outpatient follow-up appointments with Medical Oncology and colorectal Surgery for the purpose of pursuing further workup.

Results/Outcomes: The patient underwent a colonoscopy several days after presenting to the ER. The colonoscopy showed numerous flat lesions throughout the entire colon and terminal ileum. Biopsies were taken from the terminal ileum, appendiceal orifice, ileocecal valve, ascending colon, flat lesions in the descending and transverse colon, diverticulum in the sigmoid colon, flat lesion and a single, sessile 3 mm polyp in the distal rectum. The biopsies demonstrated colonic mucosa exhibiting diffuse involvement by small to intermediate-sized lymphocytes. Flow cytometry demonstrated immunophenotypic characteristics of MCL. These findings supported a diagnosis of mantle cell lymphoma. Subsequent PET-CT also showed nodal involvement in the neck, chest as well as spleen. The patient was treated with multiple cycles of Rituximab and Bendamustine due to her high disease burden. Her PET-CT at 6 months follow up showed complete resolution of nodal disease in her neck, chest, abdomen and pelvis.

Conclusion/Discussion: Mantle cell lymphomas of the GI tract are rare entities with even less incidence in the colon compared to the rest of the GI tract. The current therapeutic approach for Mantle cell lymphoma is based on the patient’s symptoms, history and stage of the disease. For patients in good clinical status and are younger than 65 years old, upfront immunotherapy induction regimen of Rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) followed by autologous stem cell transplantation is the recommended standard treatment. For patients who are older or not in good clinical status, only R-CHOP is recommended. To conclude, mantle cell lymphoma of the GI tract can be a very aggressive disease that warrants early aggressive diagnosis and treatment.