Lymphocytic aleukemic leukemia cutis.

A 21-year-old male patient had localized papules on the chest and arms. Biopsy of a lesion showed it to be a malignant lymphoid neoplasm, and immunohistochemical studies confirmed a lymphoblastoma origin. Aberrant lymphoid cells were noted in the cutaneous blood vessels, but simultaneous examination of the peripheral blood showed no evidence of leukemia. One month elapsed before observable leukemic cells were found in the blood and sternal marrow, confirming the diagnosis of acute lymphocytic leukemia. Examination of a cutaneous biopsy specimen led to early diagnosis of the disease.