1913 A Unique Presentation of Asymptomatic Mantle Cell Lymphoma at Screening Colonoscopy: Beware of a Lumpy-bumpy Mucosa

Abstract

INTRODUCTION: Mantle cell lymphoma (MCL) is a rare aggressive subtype of non-Hodgkin’s lymphoma. Most cases of MCL initially present with diffuse lymphadenopathy. The gastrointestinal (GI) tract is involved in 15–30% of cases and can manifest as a rare clinical entity called multiple lymphomatous polyposis (MLP). Because of its rarity, a clinical syndrome of MLP is not well defined and its presentation varies. Prior case reports describe the presence of GI symptoms in patients with MLP. We present an unusual case of an asymptomatic patient who was found to have MLP on screening colonoscopy and subsequently diagnosed with MCL. CASE DESCRIPTION/METHODS: A 55 year-old female presented for a screening colonoscopy with a family history of colon cancer. Her last screening colonoscopy 5 years prior was unremarkable. She denied any change in bowel movement, blood in her stool, abdominal pain, chest pain, or shortness of breath. Her CBC and CMP one year prior were unremarkable. At colonoscopy numerous small nodular, submucosal polypoid lesions with a prominent vascular pattern were found in the terminal ileum; the mucosa of sigmoid, descending, transverse, and ascending colon had a diffuse subtle nodular appearance. With narrow band imaging, numerous <1 mm nodules with atypical vascular pattern were visualized. Biopsies of all lesions were obtained for histology and flow cytometry, which confirmed a diagnosis of mantle cell lymphoma. Subsequent laboratory evaluation revealed a normal CBC and BMP, mildly elevated AST and ALT to 40–50s U/L, and an elevated LDH of 400 U/L. PET CT scan demonstrated left cervical lymphadenopathy (up to 1.9 cm), mesenteric lymphadenopathy (up to 1.2 cm), and uptake at the ileocecal junction. She was begun on a regimen of rituximab, cytarabine, and bendamustine by oncology. DISCUSSION: This case illustrates an unusual presentation of MLP in that it was discovered in an asymptomatic at time of her screening colonoscopy. It is important to recognize this rare endoscopic entity as early diagnosis and treatment improve the prognosis. The diagnosis of MLP should be considered whenever multiple submucosal polypoid lesions are encountered during endoscopy. Histopathology and flow cytometry are key to confirming the diagnosis; therefore, it is important to submit representative biopsies of these lesions for both histology and cytology to avoid delay in diagnosis, need for repeat procedures, and delay in treatment.