原发性纵隔精原细胞瘤临床病理分析

Clinicopathologic analysis of primary mediastinal seminoma

目的探讨原发性纵隔精原细胞瘤的临床病理特征和诊断要点。方法回顾性分析5例原发性纵隔精原细胞瘤的临床特点、病理学特征及免疫表达,并复习相关文献。结果 5例男性患者,年龄16~36岁,中位年龄22岁。4例为原发于纵隔的精原细胞瘤;1例首发症状为颈部淋巴结肿大,后结合临床病史及免疫组化标记确诊为纵隔精原细胞瘤转移。组织学特点为肿瘤细胞较单一、类圆形,部分胞质透亮,可见核分裂象,纤维包绕分隔成巢状或假腺状,间质内可见大量淋巴细胞浸润;免疫组化标记表达生殖细胞肿瘤标记物,OCT3/4、SALL4细胞核阳性,CD117、PLAP细胞膜阳性,淋巴造血和上皮标记均阴性。随访6~75个月,中位随访时间51个月,2例治疗后无瘤生存,2例治疗后荷瘤生存,1例失访。结论原发性纵隔精原细胞瘤具有特殊的发病部位和临床特点,容易出现漏诊或误诊,其组织学特征及免疫表达与性腺精原细胞瘤基本相同,需要结合临床病史、病理形态和免疫表型综合诊断。

Objective To investigate the clinicopathologic features and diagnosis of primary mediastinal seminoma.Methods The clinical features,pathological features and immune expression of 5 cases of primary mediastinal seminoma were retrospectively analyzed,and the relevant literatures were reviewed.Results Five male patients aged 16 to 36 years old with a median age of 22 years.Four cases were primary mediastinal seminoma,while the other one case had cervical lymphadenopathy,combined with clinical history and immunohistochemical marker to diagnose the metastasis of mediastinal seminoma.Histologically,the tumor cell was relatively single and round,with some cells have bright cytoplasm and visible mitotic images,which can be divided into nests or pseudoadenoids by fibrous septa and a large number of lymphocytes were infiltrated in the stroma;immunohistochemical expressed germ cell tumor markers.OCT3/4 and SALL4 were nuclear positive,CD117 and PLAP cell membranes were positive,lymphohematopoietic and epithelial markers was negative.Follow-up ranged from 6 to 75 months,the median follow-up period was 51 months,2 cases survived without tumor,2 cases survived with tumor and 1 case lost.Conclusion Primary mediastinal seminoma has special site and clinical characteristics,which is easy to be missed or misdiagnosed.The histological features and immune expression are basically the same as those of gonadal seminoma.Comprehensive diagnosis should be combined with clinical history,pathological morphology and immunophenotype.