POWER OF THE MAC (MORPHOLOGY-ANTIBODY-CHROMOSOMES) METHOD IN DISTINGUISHING REACTIVE AND CLONAL CELLS - REPORT OF A PATIENT WITH ACUTE LYMPHATIC-LEUKEMIA, EOSINOPHILIA, AND T(5 14)

We present a patient with acute lymphatic leukemia, eosinophilia, and a 5;14-translocation, a rare but well-documented condition. In order t o clarify whether granulocytes were involved in the disease, we applie d the MAC (Morphology-Antibody-Chromosomes) technique to samples of th e bone marrow and, during a central nervous system relapse, to those o f the cerebrospinal fluid. The karyotype of the blast cells was 47,XY, + X,t(5; 14)(q31;q32),i(7)(q10). Interphase cytogenetic study by in s itu hybridization with an X-specific alphoid probe revealed the abnorm ality in CD10, CD19, and TdT (terminal deoxynucleotidyl transferase) p ositive lymphoid cells, whereas CD 1 3 positive, Sudan black B positiv e, eosinophilic, and basophilic granulocytes as well as monocytes and small lymphocytes did not have the abnormality. Our results show that the eosinophilic and basophilic granulocytes in this subtype of acute leukemia do not belong to the malignant clone but are reactive. This s tudy also confirmed the usefulness of the MAC technique in distinguish ing neoplastic and reactive cells in malignancy. Genes Chrom (C) 1993 Wiley-Liss, Inc.