Removal of abnormal clone of leukaemic cells by splenectomy.

A patient with chronic myelocytic leukaemia positive for the Philadelphia (Ph-1) chromosome underwent splenectomy in the "terminal phase" of his disease. Chromosomal analysis of a marrow aspirate obtained during the operation showed nothing abnormal. Material from the spleen, however, showed the absence of a C chromosome and the presence of a "marker" chromosome in all metaphases examined. The patient did well for almost three years after splenectomy, and serial cytogenetic studies of marrow specimens showed the Ph-1 chromosome to be the only significant abnormality. Six months before death from recurrent blastic transformation aneuploidy was found in a marrow specimen. Subsequently additional abnormalities, including cells with two Ph-1 chromosomes, were detected. The karyotypic abnormalities found in the splenic specimen, however, never recurred.