Granulocytic sarcoma: an unusual complication of acute promyelocytic leukemia causing cerebellar hemorrhage. Case report.

Granulocytic sarcomas are rare tumors that occur primarily in patients with acute myelogenous leukemia or other myeloproliferative disorders, are seldom seen in patients with acute promyelocytic leukemia (APL), and have never been reported to occur in the cerebellum. The authors describe the case of a patient with APL who harbored a hemorrhagic granulocytic sarcoma in the cerebellum. This 39-year-old woman presented with cerebellar ataxia. Magnetic resonance images revealed an intraaxial tumor in the cerebellum. Bone marrow samples showing infiltration by leukemic blast cells and data from hematological tests led to a diagnosis of APL. The patient was treated with chemotherapy and surgery. She had no response to chemotherapy and died of progressive intratumoral hemorrhage. Results of histopathological studies and immunohistochemical staining of the cerebellar tumor confirmed a granulocytic sarcoma. Flow cytometry showed that the blast cells were positive for leukocyte common antigen, CD13, and CD33 markers. Bone marrow cytogenetics revealed that the patient had a 46,XX karyotype. Although no cytogenetic abnormality was present, fluorescence in situ hybridization detected a chimeric fusion of PML and RARA. This is the first report to document a granulocytic sarcoma in the cerebellum as the primary presentation in a patient with APL and abnormal coagulation. As predicted by the unusual clinical manifestations and radiological findings, the patient's survival was short. Although central nervous system complications in patients with APL are rare, the data in this case highlight the need for individualized treatment when such conditions occur.