An unusual expression of cALL antigen on blast cells in a patient with acute myelomonocytic leukemia

: The authors describe a case of myeloid leukemia of the myelomonocytic type (M4, FAB 1976) where blastic cells bear the lymphoblastic cALL sign. These cases of the so-called hybrid phenotype of acute leukemia are rare. The importance of the hybrid phenotype for the course and prognosis of the disease is not known.