Acute monocytic leukemia presenting as cutaneous involvement.

Specific cutaneous lesions appearing during acute monocytic leukemia (AMoL) are more frequent than those associated with other types of leukemia. However, skin involvement preceding the presence of leukemic cells in the peripheral blood is quite rare. In this paper, we describe a case where a 25-year-old male had multiple infiltrative erythemas and nodules on his arms. Histologically, the nodules were formed by masses of tumor cells in the dermis. Peripheral-blood tests revealed no abnormalities, but bone marrow aspiration from the sternum led to a diagnosis of AMoL. The diagnosis of specific cutaneous lesions of AMoL was confirmed by the results of cytochemical studies of bone marrow smears, and cutaneous nodules of cutaneous biopsy specimens led to early diagnosis. Complete remission was achieved with combination chemotherapy and peripheral blood stem cell transplantation.