Acute lymphoblastic leukemia hand-mirror cells. Study of nine cases

Acute lymphoblastic leukemia with hand-mirror cells (HMC) was diagnosed in nine adult patients. Blast HMC were seen only in the bone marrow (12-57% range). Cytochemical studies revealed a positive reaction to tartrate-sensitive acid phosphatase in the tail portion of the cells in seven cases, with a strong, localized cytoplasmic reaction in four. Leukemic cells lacked surface immunoglobulins and were E rosette negative in all cases. Normal levels of adenosine deaminase activity (ADA) were found in five of the seven patients. Electron microscope studies confirmed the hand-mirror shape of the cell. These HMC contained large numbers of mitochondria and microspikes in the handle portion of the cell. The patients failed to respond to initial conventional ALL chemotherapy, but the prolonged survival with passable health of the majority of these, despite their lack of complete remission, is emphasized.