Leiomyosarcoma metastatic to the orbit: diagnosis of fine-needle aspiration.

A 47-yr-old man with history of metastatic low-grade rectal leiomyosarcoma presented with progressive protrusion of his left eye due to an enlarging orbital mass. The differential diagnosis included tumor metastasis or orbital infection due to an unknown infectious agent. Diagnostic fine-needle aspiration (FNA) of the orbit was performed on an urgent basis to institute proper therapy and to save the patient's eyesight. Cytomorphologic examination of the material demonstrated a spindle-cell neoplasm consistent with metastatic leiomyosarcoma. It is a rare event for leiomyosarcoma to occur in the orbit. On our review of the literature, the cytology of primary orbital leiomyosarcoma on FNA has only been reported once. To our knowledge, this is the first report of the FNA cytomorphology of metastatic leiomyosarcoma to the orbit.