男,20岁,咳嗽、胸痛2个月,加重半月入院。体查见右前胸局限隆起,有轻压痛。胸片示右上纵隔有18×16cm大的阴影,密度较高,均匀,边缘光滑清楚。考虑纵隔肿瘤,胸腺瘤可能性较大。剖胸探查见肿瘤位于前上纵隔,约18×16cm大,有完整包膜,病理诊断纵隔内胚窦瘤。术后半年死于肿瘤复发。 Male, 20 years old, had cough, chest pain for 2 months, and he was admitted to the hospital half an month later. The physical examination showed that the right frontal area had limited bulges and there was mild tenderness. The chest radiograph shows a large shadow of 18×16 cm in the right upper mediastinum, which is dense and uniform with smooth and clear edges. Considering mediastinal tumors, thymoma is more likely. Thoracic exploration revealed that the tumor was located in the anterior superior mediastinum, which was approximately 18 x 16 cm in size and had a complete capsule. Pathological diagnosis of mediastinal sac tumors. Half a year later died of tumor recurrence.