Myxoid liposarcoma of the anterior mediastinum. Diagnosis by fine needle aspiration biopsy.

The mediastinum is an uncommon primary site of liposarcoma, which constitutes < 1% of tumors at that site. We report a case of myxoid liposarcoma evaluated with fine needle aspiration biopsy in a 66-year-old male who presented with cardiac tamponade, superior vena cava syndrome and radiologic evidence of a large anterior mediastinal mass. Cytologically the neoplastic cells were strikingly dyscohesive, with ovoid or spindle-shaped, hyperchromatic nuclei. The cytoplasm was abundant and often finely vacuolated with lipid. They were associated with a prominent myxoid, intercellular substance and distinct, arborized capillary structures. Survival is influenced by the tumor cell type and differentiation. The overall prognosis seems to be poorer than that of liposarcomas occurring in other areas. To the best of our knowledge, this is the first reported case of primary mediastinal liposarcoma diagnosed by fine needle aspiration biopsy.