Possible cytogenetic marker associated with myelofibrosis in chronic granulocytic leukemia and its prognostic significance.

An association between myelofibrosis (MF) and chronic granulocytic leukemia (CGL) has been recognized. MF is usually a sign of a poor prognosis but its relation to other important parameters of CGL is not known. We observed a 54-year-old, white male patient who was well until May 1983 when he began developing gradually increasing right hip and left shoulder pain. Clinical evaluation 3 months later revealed splenomegaly and a white blood count of 126,000 with 29 segmented neutrophils, 22 bands, 7 metamyelocytes, 11 myelocytes, 6 promyelocytes, 5 blasts, 2 eosinophils, 5 basophils, and 3 lymphocytes. Cytogenetic analysis by G-banding technique showed a male karyotype with all 20 bone marrow cells examined positive for the Philadelphia chromosome. The patient was placed on busulfan therapy with good symptomatic improvement, but later suffered severe thrombocytopenia. At the end of October 1983, he was admitted with blast crisis and thrombocytopenia and was initiated on vincristine and cytosine arabinoside therapy. His bone marrow was repeatedly inaspirable and the biopsy was characterized by diffuse fibrosis. Chromosome analysis of 16 spontaneously dividing cells in the blood at this time revealed that 86% of cells had a karyotype of 46,XY,t(9;22)(q34;q11),t(1;3)(p32;p21) with the rest of the cells having only the Ph chromosome. The patient died 4 months later of intracranial hemorrhage. Chromosome #3 involvement has been reported in acute MF and essential thrombocytosis, but no specific cytogenetic abnormalities have been found in MF associated with CGL. It is unclear whether t(1;3) in this case represents a cytogenetic marker of MF or blast transformation, but it is certainly associated with poor prognosis and short survival.