Uncommon simultaneous diagnosis of multiple myeloma and chronic myeloid leukaemia

Chronic myeloid leukaemia (CML) is a clonal hematopoietic stem cell disorder. The annual incidence of CML is 1.5 cases per 100,000 individuals. Multiple myeloma (MM) represents a malignant proliferation of plasma cells derived from a single clone. The co-occurrence of two rare malignancies CML and MM in the same patient is an extremely rare incident, and simultaneous diagnosis of CML and MM is reported in only five cases in the literature. A 75-year-old male presented with complaints of easy fatigability, loss of appetite and unquantifed weight loss of four months' duration. On evaluation he was found to have normocytic normochromic anaemia, leucocytosis, elevated serum-calcium concentration and azotaemia. Peripheral blood for the BCR-ABL fusion gene product was positive by flourescence in situ hybridisation (FISH). However, bone marrow biopsy revealed CD138 positive, 15% plasma cells. Thus the diagnosis of CML and MM was established. Although we can't be certain regarding the cause of CML and MM in our patient, the hypothesis that they evolved from common malignant pluripotent hematopoietic stem cells still holds. However, at the age of 75 years, it might be just due to chance.