Yoshino Ryusei, Ujiie Nanami, Yasuda Shunsuke, Kamikokura Yuki, Kitada Masahiro
Department of Thoracic Surgery and Breast Surgery, Asahikawa Medical University Hospital, Asahikawa, Hokkaido, Japan.
Department of Diagnostic Pathology, Asahikawa Medical University Hospital, Asahikawa, Hokkaido, Japan.
Surg Case Rep. 2025;11(1). doi: 10.70352/scrj.cr.25-0091. Epub 2025 Jul 1.
Although seminomas typically arise in the testes, primary mediastinal seminomas are classified as extragonadal germ cell tumors. Diagnosis is often challenging and requires not only blood tests and imaging but also a tumor biopsy. However, diagnosis may be particularly difficult when the tumor shows nonspecific pathological features or is accompanied by granulomatous changes.
The patient was a 25-year-old man who had been experiencing labored breathing when leaning forward for the past month. Physical examination revealed distended jugular veins and neck edema. Chest computed tomography revealed an irregular mass measuring 80 mm in the anterior mediastinum, suggesting invasion of the superior vena cava. Additionally, fluorodeoxyglucose-positron emission tomography showed high accumulation in the same area, with a maximum standardized uptake value of 11.3. A tumor biopsy was performed under thoracoscopic guidance for definitive diagnosis. Histopathological examination of the resected specimen revealed a seminoma with granulomatous changes. Based on these findings, a diagnosis of anterior mediastinal seminoma with superior vena cava syndrome was made. It was classified as having a good prognosis, and the patient received three courses of induction chemotherapy with etoposide, cisplatin, and ifosfamide. Complete remission was achieved. Since then, the patient has been monitored every 3 months, with no recurrence or metastasis observed for approximately 2 years.
Immunohistochemical analysis plays a crucial role in the accurate diagnosis of mediastinal seminomas, especially in cases with unusual histological features such as granulomatous changes. Recognizing the immunoprofile of seminomas and differentiating them from thymomas and lymphomas is essential for avoiding diagnostic pitfalls.
虽然精原细胞瘤通常起源于睾丸，但原发性纵隔精原细胞瘤被归类为性腺外生殖细胞肿瘤。诊断往往具有挑战性，不仅需要血液检查和影像学检查，还需要进行肿瘤活检。然而，当肿瘤表现出非特异性病理特征或伴有肉芽肿性改变时，诊断可能会特别困难。
患者为一名25岁男性，在过去一个月里向前倾时一直感到呼吸困难。体格检查发现颈静脉扩张和颈部水肿。胸部计算机断层扫描显示前纵隔有一个不规则肿块，大小为80毫米，提示上腔静脉受侵。此外，氟脱氧葡萄糖-正电子发射断层扫描显示同一区域有高摄取，最大标准化摄取值为11.3。在胸腔镜引导下进行了肿瘤活检以明确诊断。对切除标本的组织病理学检查显示为伴有肉芽肿性改变的精原细胞瘤。基于这些发现，诊断为前纵隔精原细胞瘤伴上腔静脉综合征。其被归类为预后良好，患者接受了依托泊苷、顺铂和异环磷酰胺的三个疗程诱导化疗。实现了完全缓解。从那时起，每3个月对患者进行监测，约2年未观察到复发或转移。
免疫组织化学分析在纵隔精原细胞瘤的准确诊断中起着关键作用，尤其是在具有不寻常组织学特征（如肉芽肿性改变）的病例中。认识精原细胞瘤的免疫表型并将其与胸腺瘤和淋巴瘤区分开来对于避免诊断陷阱至关重要。
