睾丸消退性生殖细胞肿瘤3例临床病理学分析

Burned-out testicular germ cell tumors:a clinicopathological analysis of three cases

目的探讨睾丸消退性生殖细胞肿瘤的临床病理特征及鉴别诊断。方法回顾性分析上海交通大学医学院附属瑞金医院2016至2020年收治的3例睾丸消退性生殖细胞肿瘤的临床、影像学资料、病理形态学和免疫表型特征,并复习相关文献。结果3例患者平均年龄32岁。例1术前甲胎蛋白水平升高(810.18μg/L),因腹膜后占位行“根治性胰十二指肠切除术+腹膜后病损切除”。术后病理示胚胎性癌,需除外性腺转移,行彩超见右侧睾丸实性占位,部分区域低回声伴散在钙化。例2为“右锁骨上淋巴结穿刺标本”,胸片提示双肺多发转移灶,穿刺活检病理示转移性胚胎性癌,行双侧睾丸彩超见右侧睾丸内异常钙化灶。例3因发现右侧睾丸囊实性占位伴钙化。3例均行“根治性右侧睾丸切除术”。大体观察:睾丸瘢痕区界限清楚,灰白-棕黄,单灶或多灶,最大径0.6~1.5 cm。镜下观察:瘢痕内见淋巴细胞和浆细胞浸润、玻璃样变的管状结构影、簇状血管增生、吞噬含铁血黄素的巨噬细胞;瘢痕周边见萎缩和硬化的生精小管、簇状的间质细胞(Leydig cells)增生、管内微小或粗颗粒状钙化,其中例1见精原细胞瘤和原位生殖细胞肿瘤,例2见原位生殖细胞肿瘤,例3见生精细胞不典型增生。免疫表型:胚胎性癌表达SALL4、广谱细胞角蛋白(CKpan)和CD30;精原细胞瘤和原位生殖细胞肿瘤表达OCT3/4、SALL4、CD117;不典型增生的生精细胞表达CD99和SALL4,Ki-67阳性指数约20%,而OCT3/4、CD117均阴性。结论睾丸消退性生殖细胞肿瘤罕见,性腺外的生殖细胞肿瘤首先要考虑到来自性腺睾丸转移的可能性,如果在睾丸内发现瘢痕,一定要判断是否为睾丸消退性生殖细胞肿瘤,消退机制可能与肿瘤免疫介导和局部缺血性损伤的微环境有关。

Objective To investigate the clinicopathological features and possible mechanisms of burned-out testicular germ cell tumors.Methods The clinical and imaging data,histology and immunophenotypic characteristics of three cases of burned-out testicular germ cell tumors diagnosed at the Ruijin Hospital,Medical College of the Shanghai Jiaotong University,from 2016 to 2020 were retrospectively analyzed.The relevant literature was reviewed.Results The mean age of the three patients was 32 years.Case 1 had an elevated preoperative alpha-fetoprotein level(810.18μg/L)and underwent"radical pancreaticoduodenectomy and retroperitoneal lesion resection"for a retroperitoneal mass.Postoperative pathology showed embryonal carcinoma,which needed to exclude gonadal metastasis.Color Doppler ultrasound showed a solid mass of the right testis,with hypoechoic lesion and scattered calcification in some areas.Case 2 was a"right supraclavicular lymph node biopsy specimen."Chest X-ray showed multiple metastases in both lungs.The biopsy showed metastatic embryonic carcinoma and bilateral testicular color Doppler ultrasound revealed abnormal calcifications in the right testicle.Case 3 showed a cystic mass of the right testis with calcification and solid areas.All 3 patients underwent radical right orchiectomy.Grossly,borders of the testicular scar areas were well defined.Cross sectioning of the tumors showed a gray-brown cut surface and single focus or multiple foci of the tumor.The tumor maximum diameter was 0.6-1.5 cm.Microscopically,lymphocytes,plasma cells infiltration,tubular hyalinization,clustered vascular hyperplasia and hemosiderin laden macrophages were found in the scar.Atrophic and sclerotic seminiferous tubules,proliferation of clustered Leydig cells and small or coarse granular calcifications in seminiferous tubules were present around the scar.Seminoma and germ cell neoplasia in situ were seen in case 1,germ cell neoplasia in situ was seen in case 2 and germ cells with atypical hyperplasia were seen in case 3.Immunohistochemistry showed that embryonic carcinoma expressed SALL4,CKpan(AE1/AE3)and CD30,seminoma and germ cell tumor in situ expressed OCT3/4,SALL4 and CD117,and spermatogenic cells with atypical hyperplasia expressed CD99 and SALL4.The Ki-67 positive index was about 20%,while OCT3/4 and CD117 were both negative.Conclusions Burned-out testicular germ cell tumors are rare.The possibility of gonad testicular metastasis should be considered first for extragonadal germ cell tumor.If fibrous scar is found in testis,it must be determined whether it is a burned-out testicular germ cell tumor.The burned-out mechanisms may be related to the microenvironment of tumor immune-mediated and local ischemic injury.