[The diagnostic value of T- and B-rosette formation and the unspecific acid esterase in the differential diagnosis of acute and chronic leukemia]

The diagnostic significance of acid non-specific alpha-naphthyl-acetate (ANAE) and of rosette formation of leukemic cells with sheep and mouse erythrocytes was studied in 8 patients with acute myeloic leukemia (AML), in 4 patients with acute lymphatic leukemia (ALL) and in 14 patients with chronic lymphatic leukemia (CLL). ANAE showed typical diffuse cytoplasmic activity in all cases of AML. The enzyme activity was granular in both of the lymphoid malignancies, T-ALL and B-CLL, allowing differentiation from AML but not between B- and T-leukemia cells. Rosette formation with mouse erythrocytes (ME) was diagnostic in all 14 cases of CLL and superior to labeling of surface immunoglobulin (8 of 14 cases positive). ME-rosette forming myeloblasts were detected in 2 of 4 evaluated cases of AML. Rosette formation with sheep erythrocytes (SE), including cytological evaluation of rosette-forming cells, was diagnostic in all cases of ALL (= T-ALL). In 6 of 9 patients with AML, however, rosette formation with SE was observed in a few cells, including myeloblasts with Auer rods. The occurrence of blasts in myeloic leukemia carrying lymphoid cell markers is discussed in the light of recent findings, according to which lymphoblastoid cells may arise in the course of myeloic leukemia requiring antileukemic treatment different from that of AML.