Chronic myelogenous leukemia that occurred two years after the diagnosis of adult Still's disease.

A 25-year-old Japanese man was diagnosed with steroid-resistant Adult Still's Disease (ASD) in August 2000. No evidence of chronic myelogenous leukemia (CML) had been found during admissions in 2000 and 2001. In August 2002, he was diagnosed with CML with a peripheral white blood count of 69,940/microl and positivity for Philadelphia chromosome and BCR/ABL fusion gene on bone marrow aspiration. No case of CML was reported to develop from ASD. Because a diagnosis of ASD is based on the exclusion of other diseases, we must be cognizant of the possibility of the development of concurrent diseases.