[CD3-negative natural killer cell leukemia with aggressive clinical course]

The authors report an autopsy case of CD3- large granular cell leukemia with an aggressive clinical course. A 15-year-old male was admitted to our hospital with complaint of high fever. Clinical examination revealed cervical lymphadenopathy and hepatosplenomegaly. His white blood cell count was 7,000/microliters with 45% large granular lymphocytes. A biopsy specimen of the cervical lymph node showed diffuse lymphoma, mixed small and large cells (DM). Surface marker analysis by immunohistochemical technique revealed that neoplastic cells expressed CD2, CD38, CD56 and HLA-DR but lacked CD3, CD4 and CD8. Southern blot analysis of immunoglobulin (Ig) and T cell receptor (TCR) genes showed germ line of Ig and TCR. These findings indicate that this case was a large granular cell leukemia with the natural killer cell phenotype. Despite anti-leukemic therapy, he died of hyperkalemia and acidosis. Autopsy showed a marked swelling of the liver (3,122 g) and spleen (2,434 g) with leukemic cell infiltration.