[Aggressive NK cell leukemia/lymphoma: an autopsy case]

A 67-year-old man was admitted with erythematous skin papules, lymphadenopathy and liver dysfunction. The bone marrow was filled with atypical lymphoid cells, and a skin biopsy showed diffuse dermal infiltration of neoplastic cells, which were positive for CD2, CD8, CD56, TIA-1, Granzyme B and EBER (ISH), but negative for CD3, CD4, CD16 and CD57. Molecular analysis showed a germline configuration for T-cell receptor beta, gamma chain genes, and monoclonal integration of Epstein-Barr virus. The THP-COP regimen was not effective and the patient died of severe metabolic acidosis 2 months later. Autopsy revealed diffuse infiltration of neoplastic cells in almost all organs. Apoptosis of tumor cells and proliferation of hemophagocytic macrophages were remarkable. Neither angiocentricity nor necrosis was observed. The findings in this patient were indistinguishable from advanced-stage nasal-type NK cell lymphoma. However, the diagnosis of aggressive NK cell leukemia/lymphoma may be justified because of the marked involvement of the marrow at onset, fulminant clinical course and diffuse infiltration of tumor cells evident at autopsy.