[Micronodular thymoma with lymphoid stroma（MNT）].

We report a surgical case of MNT, which is a rare type of thymoma. A 56-year-old man was referred to our hospital for examination of a mass in the anterior mediastinum. The computed tomography (CT) scan showed a lobulated mass with relatively smooth margins. Also, contrast study indicated homogeneous enhancement. Since these findings suggested the possibility of thymoma, the patient underwent thymothymomectomy. Histological findings showed short spindleshaped tumor cells forming nests of various sizes, and lymphoid stroma with lymphoid follicles. The pathological diagnosis was MNT. The long-term outcome after resection of MNT currently remains unclear, and accumulation of further cases is required.