Chronic myeloid leukemia transformation in a patient with paroxysmal nocturnal hemoglobinuria: a rare case report with literature review.

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hematopoietic stem cell (HSC) disorder arising from a somatic mutation of the X-linked phosphatidylinositol glycan complementation class A gene (PIG-A) which leads to partial or complete deficiency of glycosyl-phosphatidylinositol (GPI)-linked membrane proteins and causes intravascular hemolysis. Its pathophysiological links with aplastic anemia (AA) and myelodysplastic syndrome (MDS) have been described frequently, and few acute leukemia are proved to be derived from PNH. However, PNH with transformation to chronic myeloid leukemia (CML) has never been reported. Here, we report a patient initially diagnosed with PNH while 11 years later, Ph chromosome and BCR/ABL fusion gene were detected and the patient was eventually confirmed the diagnosis of CML. Here, the diagnosis and management of the interesting case, as well as questions regarding pathogenesis, are discussed.