Secondary Hairy Cell Leukemia in a Patient With Chronic Myelogenous Leukemia Following Treatment With Tyrosine Kinase Inhibitors: Report of an Extremely Rare Case and Review of the Literature

Abstract

The occurrence of chronic myelogenous leukemia (CML) and hairy cell leukemia (HCL) in the same patient is extremely rare. The reported cases had either CML and HCL occurring simultaneously or development of CML after HCL. We report an unusual case of CML with subsequent development of HCL after treatment with tyrosine kinase inhibitors. The diagnosis was challenging both clinically and pathologically due to the expected side effects of tyrosine kinase inhibitors and low levels of hairy cells initially. We further showed that the CML and HCL are not clonally related, in contrast to the only case in which clonality study was performed. To our knowledge, this is the first report of HCL developing in patients with CML. J Med Cases. 2012;3(1):39-42 doi: https://doi.org/10.4021/jmc404w