Cytogenetic studies of peripheral myeloblasts and bone marrow fibroblasts in acute myelofibrosis.

Chromosome analysis with giemsa-trypsin banding was performed on circulating myeloblasts and cultured bone marrow fibroblasts from a patient with acute myelofibrosis. Major karyotypic abnormalities were found in the myeloblasts involving chromosomes #1, 3, 5, 13, and 16; no chromosome abnormalities were detected in the fibroblasts. In addition, a pericentric inversion of number 7 was present in the circulating blasts but not the fibroblasts. Pericentric inversions have not previously been associated with acquired abnormalities of malignant cells. These findings support the concept that acute myelofibrosis is a primary malignancy of hematopoietic cells associated with secondary marrow fibrosis. The entity of acute myelofibrosis is discussed and the results of cytogenetic studies of previous reports are reviewed.