Case 007: 57 Year Old Female with Left Renal Mass
on the Scalp

Contributed by Andre Thompson, M.D., Supervised by Alan Boom, M.D.

Clinical History

The patient is a 57-year-old diabetic female who presented to the ER with shortness of breath. She was admitted with the following diagnoses: hypoxia, splenomegaly, anemia (HCT 27.9), leukocytosis (WBC 11.7) with bandemia (bands <50%), and spinal stenosis (C6 to C7). She was placed on intravenous gatifloxacin and Solu-Medrol. CT with contrast of the abdomen and pelvis revealed left infiltrative renal mass with lymphadenopathy, and pericardial effusion. Renal biopsy was performed.

Gross Findings

The specimen is a 1.5 cm gray-tan, needle biopsy.

Microscopic Findings

(Click a photo to view a larger image.)

Image (1)  H&E, 2x Image (2)  H&E, 4x Image (3)  H&E, 20x Image (4)  H&E, 40x Image (5)  H&E, 40x Image (6)  CD20, 10x Image (7) CD3, 10x

Diagnosis

Burkitt lymphoma - Immunoperoxidase stains performed on the neoplastic cell population demonstrated strong positive staining for CD20 and negative staining for CD3. Material submitted for flow cytometric immunophenotyping from the corresponding fine needle aspirate demonstrated a monoclonal population of B lymphoid cells with expression of CD19, CD10, and CD20, with lambda light chain restriction. The immunophenotypic and morphologic features support a diagnosis of Burkitt lymphoma.

Discussion

Burkitt lymphoma is a very aggressive tumor of mature B cells. It is the most rapidly growing of all lymphomas, with 100% of the cells in the cell cycle at any time.

Three, morphologically identical, clinical variants of this tumor have been described: (1) endemic (African) Burkitt lymphoma, (2) sporadic Burkitt lymphoma, and (3) AIDS-associated Burkitt lymphoma. Children and young adults are more frequently affected.

Most cases of Burkitt lymphoma present with an extranodal mass. Endemic cases often present as a mass involving the mandible and show an unusual predilection for abdominal viscera, particularly the kidneys, ovaries, and adrenals. Sporadic Burkitt lymphoma, on the other hand, usually presents with an abdominal mass involving the ileocecum or peritoneum. Involvement of bone marrow and peripheral blood (Burkitt leukemia) is uncommon.

Translocation t(8;14) involving the c-MYC oncogene on chromosome 8 is present in 85% of Burkitt lymphomas. Other translocations of c-MYC (t(2;8) and t(8;22)) are found in the rest of the cases. Essentially all the endemic cases are associated with latent EBV infection compared to 25% of HIV-associated tumors and 15-20% of sporadic tumors.

Morphologically, the involved tissue is effaced by a diffuse infiltrate of monomorphic, medium-sized lymphoid cells that have round-to-oval nuclei with coarse chromatin, 2-5 basophilic nucleoli, and a moderate amount of basophilic or amphophilic cytoplasm. Numerous mitotic figures and apoptotic cells are typically found. On low power, the starry sky pattern characteristic of Burkitt's lymphoma is a manifestation of the numerous benign macrophages that have ingested karyorrhectic or apoptotic tumor cells.

Burkitt's lymphoma has a mature B-cell immunophenotype. The cells express CD19, CD20, CD22, CD79a, and monoclonal sIg, which is usually IgM with light-chain ? or ? restriction. Most cases are CD10+ and consistently CD5- and CD23-. Nuclear Bcl-6 is typically present (without BCL-6 rearrangement), and CD5, CD34, BCL2 and TdT are typically absent.