Intraparenchymal myeloid sarcoma and subsequent spinal myeloid sarcoma for acute myeloblastic leukemia.

Myeloid sarcoma is a solid, extramedullary tumor composed of leukemic myeloblasts or immature myeloid cells. Intraparenchymal myeloid sarcoma without the involvement of the skull or meninges is extremely rare. Here, we present the case of a 49-year-old man who developed intraparenchymal myeloid sarcoma on the left cerebellum after allogeneic bone marrow transplantation (BMT). He received radiotherapy after complete removal of intraparenchymal myeloid sarcoma, but he was diagnosed spinal myeloid sarcoma three month later. Nine months after the operation, new intracranial and spinal myeloid sarcoma were diagnosed and the patient's condition had been worsened rapidly. Although the spinal myeloid sarcoma was not histologically diagnosed, this report provides valuable insights into the clinical course of progression of intraparenchymal myeloid sarcoma.