Aleukemic monocytic leukemia cutis.

Aleukemic leukemia cutis is a rare condition in which leukemic cells invade the skin before they appear in peripheral blood or bone marrow specimens. Herein we describe a 67-year-old man who underwent assessment because of papules and nodules on his back and lower extremities. A biopsy of these lesions confirmed a dense, predominantly monocytic infiltrate of the dermis and subcutaneous tissue. Immunohistochemical stains were positive for CD43 (Leu-22) as well as monocytic markers. Bone marrow and peripheral blood examinations failed to reveal leukemia. Treatment was based on the results of the skin biopsy, and the patient is doing well 1 year after therapy.