Philadelphia Chromosome Abnormality in Agnogenic Myeloid Metaplasia

Abstract

Cytogentic studies were carried out on a patient with typical agnogenic myeloid metaplasa because of the finding of a low leucocyte alkaline phosphatase. The modal chromosome number was 46. An abnormal chromosome in group No. 21 resembling the Ph1 chromosome was found in 11.7% of the cells with 46 chromosomes. The Ph1 chromosome is present in virtually every case of clinically typical chronic granulocytic leukemia and is absent in other conditions which resemble it, including agnogenic myeloid metaplasia in previously reported studies. The significance of the Ph1 chromosome abnormality has been discussed. It is suggested that the patient described has either leukemia masquerading as agnogenic myeloid metaplasia or both conditions. Further cytogenetic studies of patients with myeloproliferative disorders may clarify their interrelationship.