Inflammatory malignant fibrous histiocytoma of thymus origin.

A 46-year-old man was referred to our department complaining of anterior chest pain. A chest computed tomographic scan revealed an anterior mediastinal tumor measuring 38 x 35 x 50 mm. Suspecting a thymoma, we performed extended thymectomy through a median sternotomy under general anesthesia. Pathologically, the tumor was composed of pleomorphic spindle-shaped cells arranged in a storiform pattern, with marked inflammatory cell infiltration. The tumor was contiguous with the thymus tissue. Based on these findings, we made the diagnosis of inflammatory malignant fibrous histiocytoma originating from the thymus. Until now, 12 months later, the patient has shown no evidence of tumor recurrence.