Background In a patient with a germline BRCA2 pathogenic variant with breast cancer, an adnexal mass can represent either a metachronous primary tumor or a metastasis of the breast cancer. A clear distinction between those two possibilities is crucial since treatments differ substantially and so does survival of the patient. Case presentation We present a case of a 47-year-old patient with bilateral breast carcinoma with a germline BRCA2 pathogenic variant. The first manifestation of the disease was a lump in her left breast in 1998, histological report was invasive ductal carcinoma, triple-negative. She was treated with surgery, chemotherapy and radiotherapy. In 2011 a new occult carcinoma was found in her right axilla, however the specimen was estrogen receptor (ER) and progesterone receptor (PgR) positive. She was treated as a new primary occult carcinoma of the right breast with surgery, radiotherapy and adjuvant hormonal treatment. In 2016 a mass in the left adnexa was found with imaging techniques. She underwent surgery as if it was primary ovarian cancer, yet histology revealed it was a metastasis of a triple-negative breast carcinoma in the fimbrial part of the left Fallopian tube. She received adjuvant chemotherapy after surgery and is now in complete remission. Conclusion We present an interesting and quite rare case of two primary breast carcinomas in a patient with a known BRCA2 pathogenic variant with metastasis in the fimbrial part of the left Fallopian tube. We conclude that there were two primary breast tumours and the one from 2011 spread into the fimbrial part of the left Fallopian tube in 2016. Despite the fact that molecular analyses could not confirm the joint tumour origin, we believe that there was a receptor status conversion over time explaining different receptor status. The possibility of a triple-negative metastasis from the tumour treated in 1998 is less probable. With both of aforementioned possibilities being prognostically unfavourable, the patients’ outcome is so far excellent and she was in complete remission at the time of writing this article.

中文翻译：

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一个有趣的病例，可能是 BRCA2 相关的双侧乳腺癌，并在输卵管的菌毛部分转移

背景 在患有种系 BRCA2 致病性变异的乳腺癌患者中，附件肿块可以代表异时性原发性肿瘤或乳腺癌的转移。这两种可能性之间的明确区别至关重要，因为治疗差异很大，患者的生存率也有很大差异。病例介绍 我们介绍了一个 47 岁双侧乳腺癌患者的病例，该患者患有胚系 BRCA2 致病性变异。1998年首发表现为左乳肿块，组织学报告为浸润性导管癌，三阴性。她接受了手术、化疗和放疗。2011年，在她的右腋下发现了一个新的隐匿性癌，但标本为雌激素受体（ER）和孕激素受体（PgR）阳性。她被视为一种新的右乳原发性隐匿癌，接受了手术、放疗和辅助激素治疗。2016 年，通过成像技术发现了左侧附件中的肿块。她接受了手术，就好像它是原发性卵巢癌一样，但组织学显示它是左输卵管菌毛部分的三阴性乳腺癌转移。她在手术后接受了辅助化疗，目前已完全缓解。结论 我们提出了一个有趣且非常罕见的病例，该病例是一名患有已知 BRCA2 致病性变异并在左侧输卵管菌毛部分转移的患者中的两例原发性乳腺癌。我们得出的结论是，有两个原发性乳腺肿瘤，一个从 2011 年开始在 2016 年扩散到左侧输卵管的菌毛部分。尽管分子分析无法证实关节肿瘤起源，但我们认为随着时间的推移存在受体状态转换，解释了不同的受体状态。1998 年治疗的肿瘤发生三阴性转移的可能性较小。由于上述两种可能性都对预后不利，因此患者的预后非常好，在撰写本文时她已完全缓解。