Rare leukemia skin lesion fooled doctors treating a Tanzanian child

Doctors at Muhimbili National Hospital in Tanzania have reported an unusual pediatric case in which leukemia announced itself in the skin, masquerading as one of the region’s most feared childhood cancers. A five-year-old boy arrived with a recurrent, painless swelling in front of his left ear that had already been excised once at a peripheral hospital on the assumption that it was Burkitt lymphoma. Only after the mass returned, and after the excised tissue was sent abroad for expert review, did the full diagnostic picture emerge: the skin lesion was leukemia cutis, the cutaneous infiltration of leukemic cells, arising in the setting of B-cell acute lymphoblastic leukemia. The case report, published in Discover Medicine, illustrates how easily this rare presentation can be mistaken for lymphoma, and why comprehensive immunophenotyping matters when a childhood soft tissue mass refuses to behave as expected.

Leukemia cutis is defined as the infiltration of leukemic cells into the skin, producing lesions that can appear as papules, nodules, plaques, tumors, or diffuse erythematous eruptions. It is an uncommon manifestation of leukemia in children, occurring in fewer than five percent of pediatric leukemia cases, and it is most frequently associated with acute myeloid leukemia rather than the lymphoblastic leukemias. Crucially, the skin involvement may precede, coincide with, or follow the diagnosis of systemic leukemia. When it appears first, before any blood count abnormalities have raised suspicion, it can be extraordinarily difficult to recognize, because its clinical appearance and histopathological features overlap with infectious, inflammatory, and neoplastic skin disorders, including cutaneous lymphomas. That overlap is precisely what makes cases like this one a warning worth broadcasting.

The boy’s story began at a peripheral hospital, where he presented with a four-month history of a progressively enlarging, painless left preauricular swelling accompanied only by persistent night sweats. There was no fever, easy bleeding, weight loss, bone pain, or other constitutional symptoms. The lesion measured approximately six by four centimeters, and laboratory investigations showed moderate anemia with a hemoglobin of 9 grams per deciliter, but normal white blood cell and platelet counts. Because leukemia was not clinically suspected, no imaging studies or bone marrow examination were performed. Based on the clinical suspicion of Burkitt lymphoma, a malignancy that is highly prevalent in sub-Saharan Africa and commonly presents as a rapidly enlarging head and neck mass in children, an excisional biopsy was carried out.

The first histopathological examination proved inconclusive, and no definitive diagnosis or treatment was established. The swelling resolved completely after surgery, and the child remained clinically stable for roughly four months, apart from the ongoing night sweats. Then the lesion recurred at the same site. A second excisional biopsy was performed at the peripheral hospital, and this time the histology was more suggestive: a malignant neoplasm with a starry-sky appearance, composed of medium-sized atypical lymphoid cells, numerous tingible-body macrophages, and a high mitotic index, raising suspicion for Burkitt lymphoma. However, immunohistochemistry and immunophenotyping were unavailable at the peripheral facility, so the tissue block was referred to Dublin for expert histopathological review. Approximately three months after the recurrence, the boy was referred to Muhimbili National Hospital for further evaluation and management.

On examination in Dar es Salaam, the child appeared pale but was hemodynamically stable and well nourished. A firm, non-tender, non-ulcerated left preauricular mass, now measuring approximately six by eight centimeters, sat beneath a healed surgical scar. Ipsilateral anterior and posterior cervical lymphadenopathy was present, with the largest lymph node measuring four by four centimeters. There was no bone tenderness, hepatosplenomegaly, or additional peripheral lymphadenopathy. The new laboratory findings told a different story from the initial presentation: mild leukopenia with a white blood cell count of 3.5 billion per liter, a normal absolute neutrophil count, severe anemia with a hemoglobin of 7.0 grams per deciliter requiring transfusion of packed red blood cells, and a normal platelet count of 300 billion per liter. Compared with the moderate anemia and normal counts at first presentation, these changes suggested progression to bone marrow involvement.

Further workup filled in the picture. Serum lactate dehydrogenase was mildly elevated at 304 units per liter against a reference range of 127 to 264, while serum uric acid, liver function, renal function, electrolytes, and coagulation parameters were all within normal limits. Cerebrospinal fluid analysis showed no evidence of central nervous system disease. The Dublin review of the second skin biopsy revealed diffuse effacement of the dermis by a relatively monotonous infiltrate of small round blue cells, initially raising suspicion for lymphoma. Immunohistochemistry then changed the diagnosis: the infiltrating cells were diffusely positive for CD45, terminal deoxynucleotidyl transferase, and CD79a, and negative for CD56, CD34, CD10, and myeloperoxidase. The Ki-67 proliferation index was approximately 55 percent, with only faint patchy c-MYC expression. These findings were consistent with cutaneous infiltration by B-cell acute lymphoblastic leukemia, that is, leukemia cutis.

Bone marrow studies confirmed the systemic disease. Aspiration demonstrated 79 percent lymphoblasts, and the trephine biopsy showed extensive replacement of normal marrow by blasts. Flow cytometric immunophenotyping identified a blast population accounting for approximately 78 percent of total events, expressing dim CD45, CD19, CD79a, and TdT, while lacking CD10, MPO, and CD20, a profile consistent with B-cell acute lymphoblastic leukemia. Contrast-enhanced computed tomography of the neck showed diffuse enlargement of the left parotid gland with heterogeneous enhancement involving both superficial and deep lobes, adjacent soft tissue infiltration, and ipsilateral cervical lymphadenopathy; the radiological impression favored lymphoma. Chest radiography and abdominal ultrasonography found no thoracic or abdominal disease, and CT scans of the chest, abdomen, and pelvis were not performed.

Treatment followed the modified United Kingdom Acute Lymphoblastic Leukemia Regimen B protocol, beginning with a steroid pre-phase and then remission induction with vincristine, dexamethasone, and L-asparaginase, together with triple intrathecal chemotherapy comprising methotrexate, cytarabine, and hydrocortisone. The patient tolerated induction well, and a marked reduction in the preauricular mass was observed during induction, with near-complete clinical resolution by the end of that phase. Bone marrow assessment at the completion of induction demonstrated morphological remission, and minimal residual disease analysis by flow cytometry was negative at below 0.1 percent, indicating an excellent early treatment response. The boy subsequently received consolidation therapy, interim maintenance with escalating Capizzi methotrexate, delayed intensification, and maintenance chemotherapy. At the most recent follow-up he remained in complete clinical remission, with no recurrent skin lesions or disease progression, and continues maintenance chemotherapy in the hospital’s Pediatric Hematology-Oncology Clinic.

The authors argue that the marked clinical response to systemic chemotherapy, together with bone marrow remission and negative minimal residual disease, further supports the diagnosis of leukemia cutis secondary to B-cell acute lymphoblastic leukemia rather than primary cutaneous Burkitt lymphoma. They also note that histopathology alone may be insufficient to distinguish the two entities, because both can show diffuse infiltration by medium-sized lymphoid cells and a starry-sky appearance. Immunohistochemistry and flow cytometric immunophenotyping therefore play a pivotal role in reaching the correct diagnosis, and the case underscores the importance of integrating clinical, pathological, immunophenotypic, and bone marrow findings when evaluating atypical pediatric soft tissue masses. The absence of overt systemic leukemia features at presentation, combined with the initial inconclusive histopathology, contributed directly to the diagnostic delay.

The report carries honest caveats. Cytogenetic and fluorescence in situ hybridization analyses were not performed, which could have provided additional diagnostic confirmation and prognostic information, particularly in differentiating B-cell acute lymphoblastic leukemia from Burkitt lymphoma; the diagnosis instead rested on the combination of clinical findings, histopathology, immunohistochemistry, bone marrow morphology, and flow cytometry. As a single case report, it cannot establish how often such presentations occur or how generalizable the outcome is. Its practical message, however, is clear and grounded in the authors’ learning points: leukemia cutis should enter the differential diagnosis of persistent or recurrent pediatric head and neck masses, especially when histopathological findings are inconclusive, and early tissue biopsy, comprehensive immunohistochemistry, bone marrow examination, and flow cytometric immunophenotyping are essential for accurate diagnosis and prompt initiation of appropriate therapy.

Subject of Research: A pediatric case report of leukemia cutis mimicking Burkitt lymphoma in B-cell acute lymphoblastic leukemia

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

Article References: Munaku, H., Philbert, R., Bachuba, L., Laiti, R. H., Mwamtemi, H., Msirikale, I., Nakiddu, N. J., & Chirande, L. (2026). Leukemia cutis mimicking Burkitt lymphoma in a child at Muhimbili National Hospital, Tanzania: a case report. Discover Medicine, 3(1), Article 155. https://doi.org/10.1007/s44337-026-00690-w

Image Credits: AI Generated

DOI: 10.1007/s44337-026-00690-w

Keywords: leukemia cutis, B-cell acute lymphoblastic leukemia, Burkitt lymphoma, pediatric oncology, case report, Tanzania, immunohistochemistry, flow cytometry, bone marrow, minimal residual disease, preauricular mass, Muhimbili National Hospital