Acute myelogenous leukemia M5b developed during clinical remission of Castleman disease.

Castleman disease (CD) is a rare heterogeneous lymphoproliferative disease characterized by clinical symptoms due to an excess of interleukin-6 (IL-6) or IL-6-like activity. We describe the first case of CD associated with acute myelogenous leukemia (AML). A 55-year-old man presented with skin rash on his face and multiple cervical lymphadenopathy. The results of examination of his lymph node biopsy specimen led to a diagnosis of CD. The symptoms resolved after the administration of prednisolone. Three years after the onset of CD, the patient's white blood cell count had increased to 63.4 x 10(9)/L. His bone marrow aspirate showed that approximately 80% of cells were leukemic, including well-differentiated monocytic cells A diagnosis of AML M5b was made. The patient died of invasive pulmonary aspergillosis after chemotherapy.