Hepatosplenic T-cell lymphoma appearing in the peripheral blood.

A previously healthy 23-year-old Japanese male had complained of a fever lasting a month. A physical examination revealed marked hepatosplenomegaly without significant peripheral lymphadenopathies. Routine laboratory tests showed a hemoglobin level of 9.1 g/dL, 95 3 10/L platelets, 7.1 3 10/L leukocytes, and an elevated lactate dehydrogenase level of 522 U/L (reference interval, 120-220 U/L). A peripheral blood smear showed 2.0% atypical lymphoid cells with basophilic cytoplasm and multiple nucleoli (panel A). Bone marrow aspiration revealed 23.8% atypical lymphoid cells (panels B-C, arrows). The small cells had a scant cytoplasm and condensed chromatin, whereas the large cells had a voluminous cytoplasm and moderately dispersed chromatin. The accompanying dyshematopoiesis, including the megaloblastoid changes and pseudo-Pelger-Huët anomaly, was also recognized (arrow heads). Histological sections of the bone marrow showed the dendritic distribution of CD3/CD4/CD5/CD7/CD8/CD56/CD57/GranzymeB/TIA-1/TCRb/TCRg-lymphoid cells, suggesting their sinusoidal infiltration (panel D, stained with anti-CD3). The patient was finally diagnosed with hepatosplenic T-cell lymphoma.