Acute monocytic leukemia with translocation t(1;11) (p31;q23): simultaneous staining of chromosomes and cell surface antigens.

Cytogenetic analysis of leukemic cells from a 76-year-old patient with acute monocytic leukemia revealed the karyotype 47,XY, +8,t(1;11)(p31;q23). To the best of our knowledge this is the first case with involvement of the short arm of chromosome 1 in a t(1;11) in acute nonlymphocytic leukemia. In order to determine which hematopoietic cell lineages are involved in this case, we used a method to demonstrate chromosomes and cell surface antigens of the same cell. To identify mitoses as monocytic, erythrocytic, megakaryocytic, or lymphocytic, cell surface antigens were stained with monoclonal antibodies in an APAAP detection procedure. Subsequently, an R-banding technique was performed. About 80% of the abnormal mitoses expressed monocytic markers. No erythrocytic, megakaryocytic, or lymphocytic mitoses were found. Only an involvement of the monocytic cell lineage was revealed.