Granulocytic sarcoma (GS) is an uncommon solid tumor composed of aggregates of immature granulocytic precursors in extramedullary sites. The lesion generally occurs during the natural course of acute myelogenous leukemia or after remission has been achieved. Primary GS manifests most commonly in skin and lymph nodes, therefore when it presents in the breast, misdiagnosis of non-Hodgkin's lymphoma, lobular carcinoma, sarcoma and malignant melanoma is a common problem. The breast has been reported to be an uncommon site for GS. We report on a rare case of granulocytic sarcoma presenting as bilateral breast masses concomitant with acute myeloid leukemia in a 47-year-old woman. The patient was admitted to our hospital due to neurological manifestations, at which time we discovered lesions in the breasts. The histopathology suggested non-Hodgkin lymphoma, and chemotherapy using the CHOP regimen was performed. However, a myelogram showed hyperplasia of the granulocyte cells and immunohistochemistry tests were positive for myeloperoxidase and CD68, confirming the diagnosis of primary granulocytic sarcoma of the breasts. Cytogenetic examinations did not detect anomalies. The review of microscopy and the analysis of cerebrospinal fluid confirmed the presence of infiltration in the breast and in the central nervous system by acute monoblastic leukemia (AML M5a). AML M5a protocols had been started with daunorubicin, arabinoside-C and intrathecal chemotherapy using methotrexate, arabinoside-C and dexamethasone (MADIT). One month later, the patient refused further treatment.
Granulocytic sarcoma; breast; acute myeloid leukemia
