Abstract
Myeloid sarcoma (granulocytic sarcoma or chloroma) is a tumor formed by myeloid precursor cells in any localization other than the bone marrow. It can occur without underlying acute myeloid leukemia (AML) or other myeloid neoplasms. Herein, we present a forty-two-year-old female patient who underwent surgery because of a left adnexal mass. Microscopic examination of the specimen revealed cord-like arrangement of the tumor cells with a diffuse growth of small blue cells effacing the ovarian stroma. Adult granulosa cell tumor was in the differential given the scanty cytoplasm of the tumor and in fact was the diagnosis of the referring institution. Further microscopic evaluation with immunohistochemical analysis at our institution revised the diagnosis to myeloid sarcoma. Myeloid sarcoma is a difficult tumor to diagnose due to its rarity, especially in the absence of a history of leukemia, and correct tissue diagnosis is essential for its treatment.