Cytology of ascitic fluid in a patient with granulocytic sarcoma (extramedullary myeloid tumor). A case report.

BACKGROUND: Granulocytic sarcoma (GS) is the rare extramedullary manifestation of acute myeloid leukemia that may precede or be concurrent with leukemic infiltration of bone marrow or herald blastic transformation of a chronic myeloproliferative disorder. It has been found in most body sites and shows no age or sex predilection, necessitating its inclusion in the differential diagnosis of undifferentiated neoplasms.

CASE: A 36-year-old female presented with a three-year history of abdominal pain, jaundice and fluctuating abdominal girth. Cytology of the ascitic fluid revealed myeloid cells of eosinophilic lineage at all stages of differentiation, with many undifferentiated cells. Immunohistochemical studies on a cell block confirmed the diagnosis of granulocytic sarcoma, which excluded the differential diagnoses of Hodgkin's disease, non-Hodgkin's lymphoma and Langerhans histiocytosis.

CONCLUSION: Granulocytic sarcoma may present as a serous effusion and can be diagnosed on a cytologic specimen.