Unusual Presentation of Diffuse Large B-Cell Lymphoma With Blast-Like Cells in Peripheral Blood

Abstract

Diffuse large B-cell lymphoma (DLBCL) is the most common type of adult non-Hodgkin lymphoma in the United States but is heterogeneous, with prognosis dependent on subtype. It may arise de novo or progress from a low-grade B-cell lymphoma. We report a case of a 68-year-old African American man presenting with abdominal/flank pain, night sweats, anorexia, and unintentional weight loss. At admission, CBC showed leukocytosis (52.2 thousand/mm3) with 53% lymphocytes, normal hemoglobin and normal platelet count. Manual review of the peripheral blood smear showed several (30%) large atypical cells with high N/C ratio, fine chromatin and nucleoli concerning for blasts. Hematology was consulted, and bone marrow biopsy revealed hypercellular marrow with diffuse interstitial sheets of large atypical lymphocytes and progressive maturation of reduced numbers of myeloid and erythroid elements. Excisional biopsy of the left inguinal lymph node showed effacement of normal architecture by a diffuse proliferation of immature, medium-sized cells having a starry sky pattern. Malignant cells were moderately pleomorphic, some with vesicular nuclear chromatin and prominent nucleoli, and others with clumped chromatin and irregular nuclear contours. The flow cytometry revealed a monoclonal CD19-positive B-cell population with λ light chain restriction. CD5, cyclinD-1, and TDT were negative, ruling out blastoid variant mantle cell lymphoma and acute lymphoblastic lymphoma. The cells were weakly positive for BCL2 and negative for germinal center markers (CD10, BCL6), ruling against the diagnosis of Burkitt lymphoma. The cells showed high proliferative index (100% Ki-67). The cytogenetics showed a complex karyotype, 47,XY,t(8;14)(q24;14q32),del(9)(q12q13),i(12)(p10), del(13)(q13q21)[9]). The immunophenotype and complex karyotype favored the diagnosis of DLBCL. The patient developed sepsis and died within a week of admission. DLBCL with an acute lymphoblastic leukemia-like presentation is aggressive, with a poor prognosis.