Extraskeletal osteogenic sarcoma of the mediastinum.

This report describes the clinical and pathologic aspects of a mediastinal extraskeletal osteogenic sarcoma. This is a rare tumor that presented clinically as a thymoma. The literature on extraskeletal osteogenic sarcomas is reviewed with respect to location, age, sex, treatment, and course. The potential role of fine-needle aspiration biopsy in the diagnosis of this lesion is discussed.