A case of triple thymoma that included a microscopic-sized thymoma

Abstract

We present a rare case of triple thymoma. Two tumors were detected on a preoperative chest CT image and so total thymectomy was performed. Pathological diagnosis was thymoma. Pathological findings also revealed a small thymoma that measured just 5 mm. The three tumors were encapsulated and showed the same histologic subtype (type B2). These findings suggested the possibility of multicentric genesis rather than intrathymic metastasis. Here, the pathological examination revealed an additional thymoma, one not disclosed during the operation. This suggests that thymomectomy has the possibility that small thymomas are missed. Total thymectomy should therefore be performed for thymoma.