Leukemia cutis mimicking Burkitt lymphoma in a child at Muhimbili National Hospital, Tanzania: a case report

Leukemia cutis (LC) is a rare extramedullary manifestation of leukemia resulting from infiltration of leukemic cells into the skin. Although uncommon in children, LC may represent the initial manifestation of leukemia and can clinically and histopathologically mimic other malignancies, including Burkitt lymphoma, leading to delayed diagnosis and treatment. We report the case of a 5-year-old boy who presented with a four-month history of a progressively enlarging painless left preauricular swelling associated with persistent night sweats. The lesion measured approximately 6 × 4 cm at initial presentation and was surgically excised at a peripheral hospital based on a clinical suspicion of Burkitt lymphoma. Initial histopathological examination was inconclusive. Before excision, laboratory investigations showed moderate anemia (hemoglobin 9 g/dL) with normal white blood cell and platelet counts. Four months after surgery, the lesion recurred. Repeat histopathological examination revealed diffuse dermal infiltration by monotonous small round blue cells. Immunohistochemistry showed positivity for CD45, TdT and CD79a with negativity for CD56, CD34, CD10 and MPO, supporting cutaneous involvement by B-cell acute lymphoblastic leukaemia ( Leukaemia cutis). The bone marrow flow cytometry analysis resonated with the IHC diagnosis of ALL. This case highlights leukemia cutis as an uncommon initial presentation of B-cell acute lymphoblastic leukemia that closely mimicked Burkitt lymphoma. Early tissue biopsy, comprehensive immunophenotypic evaluation, and bone marrow assessment are essential for establishing an accurate diagnosis and ensuring timely initiation of appropriate therapy.