Hand-mirror cell leukemia. Report of nine cases and a review of the literature.

In order to determine the significance of 40% or more leukemic cells in hand-mirror configuration in the bone marrow (hand-mirror cell leukemia), eight of 34 cases of acute lymphoblastic leukemia and one of 17 cases of acute myeloblastic leukemia were collected from a six-year period. Five of the eight patients who had acute lymphoblastic leukemia were children; the remaining patients were less than 40 years of age. Females outnumbered males two to one. Cytochemical and electron-microscopic studies were performed for three cases. The clinical presentations were similar to those of patients without the hand-mirror cell variant, except for a high incidence of central nervous system relapses (over 50% of patients) despite prophylaxis. When compared with patients with acute leukemia in equivalent age and morphologic categories, adults with the hand-mirror cell variant had a similar, but not better, prognosis, while children with the variant had a poorer prognosis. Additional studies must be performed to determine whether the hand-mirror cell variant warrants separation from other forms of acute leukemia.