Abstract
BACKGROUND: Benign mature teratomas are the most common type of anterior mediastinal germ cell tumor. Mature intrapericardial teratomas are generally diagnosed during infancy because of symptoms of cardiac compression. In contrast, mature adult intrapericardial teratomas are extremely rare, accounting for less than 1% of mature intrapericardial teratomas. We describe herein a case of a mature intrapericardial teratoma in an asymptomatic adult. CASE PRESENTATION: A 52-year-old woman was found by computed tomography during a health checkup to have an anterior mediastinal mass. She was asymptomatic and hemodynamically stable with no evidence of heart failure. The preoperative provisional radiological diagnosis was a mature intrapericardial teratoma. A median sternotomy revealed an approximately 5-cm diameter protruding intrapericardial mass with a smooth surface. The mass was completely resected. Histopathological examination resulted in a diagnosis of a mature intrapericardial teratoma. The patient did well and has no evidence of recurrence 5 years after surgery. CONCLUSIONS: Mature intrapericardial teratomas in adults are extremely rare. Given the risks of malignant transformation, rupture, compression of the heart, and infection, excision is indicated to prevent development of serious manifestations.