Primary Rectal Burkitt Lymphoma in a Child: A Case Report and a Review of the Literature.

Introduction: Primary colorectal lymphomas are exceptionally rare in the pediatric population, with Burkitt lymphoma representing an even rarer subset. The nonspecific symptoms can often mimic benign conditions, leading to delays in diagnosis. We report a case of primary rectal Burkitt lymphoma in a child who presented with isolated lower gastrointestinal bleeding. Case Presentation: A 10-year-old previously healthy boy presented with a 3-week history of painless, bright red blood per rectum. He had no systemic B symptoms, and his physical examination was unremarkable except for fresh blood on digital rectal examination. Initial workup revealed iron deficiency anemia and a markedly elevated serum lactate dehydrogenase. A contrast-enhanced CT scan demonstrated a large, heterogeneous mass at the rectosigmoid junction with associated mesorectal lymphadenopathy. Colonoscopy revealed multiple ulcerated polyps and a friable mass. Histopathological and immunohistochemical analyses confirmed the diagnosis of sporadic Burkitt lymphoma, characterized by a diffuse infiltrate of monomorphic lymphoid cells with a "starry-sky" appearance, positive for CD20 and CD10, and with a Ki-67 proliferation index approaching 100%. Staging investigations (bone marrow biopsy and lumbar puncture) confirmed localized disease (stage II). The patient was treated with a risk-adapted, multi-agent chemotherapy regimen (based on the FAB/LMB 96 protocol) followed by consolidative radiotherapy. He achieved complete remission, as confirmed by imaging 1 month posttreatment, and remains disease-free at his 18-month follow-up. Conclusion: This case highlights that primary rectal Burkitt lymphoma, though rare, should be considered in the differential diagnosis of persistent lower gastrointestinal bleeding in children. A high index of suspicion, combined with prompt endoscopic evaluation and biopsy, is crucial for early diagnosis. This report reinforces that with timely diagnosis and adherence to modern, risk-adapted chemotherapy protocols, even aggressive lymphomas in this unusual location can be highly curable, contributing to the limited body of literature on this rare entity.