ABSTRACT
Rheumatoid arthritis (RA) is though to be a collagen disease induced by auto-immune mechanism of unknown etiology. Chronic myelogenous leukemia (CML) is a disease characterized by overproduction of cells of the granulocytic, especially the neutrophilic series and occasionally the monocytic series, leading to marked splenomegaly and very high white blood cell counts. There's no consensus on the risk of leukemia in RA. There are some reports ragarding the relationship between low dose of methotrexate (<20 mg weekly) and the development of leukemia in RA. Although RA is a complex process, it can be considered initially as a stem cell disorder requiring treatment similar to that administered to transplant patient. We experienced a case of CML associated with RA. A 60-year-old woman with RA was treated with low dose methotrexate (7.5 mg weekly), hydroxychloroquine (HCQ), non-steroidal anti- inflammatory drug (NSAID) and low dose steroid. This therapy was continued for 3 years. She was diagnosed CML after 3 years of therapy. CML was confirmed by bone marrow biopsy and the presence of the Philadelphia chromosome.