BackgroundInguinal metastasis of endometrial cancer (EC) is rare. The aims of the study were to identify whether the inguinal metastatic tumor was originated from EC and to present the management of the disease.MethodsThe clinical data of a case of endometrioid EC “recurring” as serous adenocarcinoma in the inguinal lymph nodes were collected and analyzed. Paired samples of primary and metastatic tumors were used for exome sequencing to determine whether the tumors are same origination and to identify potential gene mutations associated with the relapse.ResultsThe patient presented with right inguinal lymphadenopathy and histopathology revealed metastatic serous adenocarcinoma. A germline MLH1 mutation was identified. A combination of bioinformatical methods and cancer-related gene exome sequencing assay identified that only 17 (0.1%) somatic gene mutations were shared by the primary EC and the metastatic inguinal tumor, suggesting that the metastasis did not originate from the primary EC. Postoperative radiation therapy followed by a combination of chemotherapy were performed. Thirty-four months after that, the patient was doing well without any evidence of recurrence.ConclusionsThis is the first case of metastatic inguinal serous adenocarcinoma in a woman with Lynch syndrome shortly after surgical treatment of stage I endometrioid EC.

中文翻译：

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子宫内膜样子宫内膜癌“复发”为生殖系 MLH1 突变林奇综合征患者腹股沟淋巴结中的高级浆液性腺癌：结果还是巧合？

背景子宫内膜癌（EC）的腹股沟转移是罕见的。该研究的目的是确定腹股沟转移性肿瘤是否起源于EC并提出该疾病的治疗方法。方法收集并分析腹股沟淋巴结中“复发”为浆液性腺癌的子宫内膜样EC病例的临床数据. 原发性和转移性肿瘤的配对样本用于外显子组测序，以确定肿瘤是否相同起源，并确定与复发相关的潜在基因突变。结果患者出现右侧腹股沟淋巴结肿大，组织病理学显示转移性浆液性腺癌。鉴定了种系 MLH1 突变。结合生物信息学方法和癌症相关基因外显子组测序分析发现，只有 17 (0. 1%) 原发性 EC 和转移性腹股沟肿瘤共有体细胞基因突变，表明转移并非源自原发性 EC。进行了术后放射治疗，然后进行了化学疗法的组合。34 个月后，患者情况良好，没有任何复发迹象。结论这是第一例发生于林奇综合征的女性在 I 期子宫内膜样 EC 手术治疗后不久发生的转移性腹股沟浆液性腺癌。