Diagnosis of granulocytic sarcoma on pleural effusion cytology: report of a case.

Granulocytic sarcoma is a rare manifestation of myeloid leukemia and is even rarer as a primary presentation. Granulocytic sarcoma may affect any organ and has many modes of presentation. Diagnosis by cytology is possible as long as the diagnosis is considered. Diagnosis by cytology of body cavity effusion fluid has rarely been described. We present an unusual case of granulocytic sarcoma in which pleural effusion was a part of the initial presentation. Cytologic examination of the pleural effusion was able to make the definitive diagnosis of granulocytic sarcoma.