Perirectal Burkitt Lymphoma Presenting as an Uncommon Cause of Lower Gastrointestinal Bleeding

A43-year-old man with a history of human immunodeficiency virus (CD4 count, 508; viral load, >1000), medical noncompliance, and polysubstance abuse presented with a 3-day history of abrupt-onset diarrhea, bright red blood per rectum, night sweats, subjective fevers, chills, and myalgias. Physical examination showed a palpable subepithelial mass on digital rectal examination. A computed tomography scan was performed showing a 5-cm right anterior perirectal mass with diffuse mesenteric lymphadenopathy. A positron emission tomography scan showed multiple large fludeoxyglucose avid lesions within the peritoneum and mediastinum and numerous large nodes in the perirectal region, concerning for lymphoma. Figure A shows a color positron emission tomography axial view of intense uptake in the perirectal region. Endorectal endoscopic ultrasound was requested for histologic confirmation and typing of presumed lymphoma. Rectal endoscopic ultrasound showed a 4.3 4.2 cm heterogeneous, hypoechoic, poorly defined mass abutting the right anterolateral rectal wall. The mass was superior to the prostate and seminal vesicles, appeared distinct from the bladder, and did not arise from the rectal wall, but appeared to abut the serosal surface of the rectum. By using a Cook 19G core needle (Cook, Bloomington, IN), fine-needle aspiration was performed and sent for pathology. Figure B shows a rectal endoscopic ultrasound with perirectal lymphadenopathy and fine-needle aspiration. Fine-needle aspiration of the perirectal mass showed sheets of atypical lymphoid cells with numerous mitotic figures and apoptotic cells (Figure C). Flow cytometry and fluorescence in situ hybridization analysis were diagnostic for Burkitt lymphoma. By using the Ann Arbor staging system, this patient was classified as stage IV (disseminated involvement of one or more extralymphatic organs), conferring a poor prognosis. The patient tolerated 4 rounds of therapy for immunodeficiency-related Burkitt lymphoma: rituximab, cyclophosphamide, doxorubicin, methotrexate, ifosfamide, etoposide, and cytarabine. This regimen was based on the standard therapy regimen for high-risk lymphoma. A follow-up positron emission tomography scan after 4 rounds of chemotherapy showed radiographic clearance, with no hypermetabolic findings in the axilla, mediastinum, or peritoneum, representing clinical remission. Burkitt lymphoma is an aggressive B-cell malignancy existing as 3 distinct clinical entities: endemic, sporadic, and immunodeficiency-associated. Characterized by the translocation of the c-MYC oncogene on chromosome 8, cases associated with human immunodeficiency virus or immunodeficiency often are related to Epstein–Barr virus infection and arise from a memory B cell or late germinal center B cell. The most common presenting symptoms in colorectal lymphoma are abdominal pain, weight loss, palpable mass, bowel obstruction, or lower gastrointestinal bleeding. Colorectal involvement only accounts for 6% to 12% of gastrointestinal lymphomas. There appear to be only sporadic case reports describing perirectal lymphoma in particular; the literature is much more robust in terms of gastrointestinal