Myeloid sarcoma of maxillary sinus

We report a case of isolated myeloid sarcoma (MS) of maxillary sinus in a patient who had no evidence of leukemia at the time of diagnosis of MS. A 39 year old healthy woman presented with right cheek swelling of one year duration. CT scan of paranasal sinuses showed an illdefined, heterogenously enhancing soft tissue density lesion in relation to right maxilla. CT findings suggested the possibility of inflammatory phlegmon with osteomyelitis. Biopsy showed a malignant round cell neoplasm which on immunohistochemistry was confirmed to be myeloid sarcoma. On follow up, one month later her peripheral blood and bone marrow showed features of Acute Myeloid Leukemia which was confirmed to be AML-M2 on Flow cytometry. The diagnosis of myeloid sarcoma has always been difficult especially when it is presenting in an unusual location in a non leukemic patient.