Chronic myelogenous leukemia after treatment with 131I for thyroid carcinoma. Report of a case and review of the literature.

A patient who developed Philadelphia chromosome-positive chronic myelogenous leukemia (CML) 5 years after successful treatment for thyroid carcinoma, is reported. The Philadelphia chromosome was the typical 9;22 translocation. Southern blot analysis showed breakpoint cluster region rearrangement as observed in classical CML. Up to now, only two cases of CML have been reported following treatment for thyroid carcinoma. This rare complication has also been described after therapy for other malignancies. At present, it is not clear whether the development of CML after thyroid carcinoma represents a therapy-induced complication, a coincidence, or an increased susceptibility to secondary malignancies due to the malignant process itself.