Kientz Caroline, Joly Marie-Odile, Faivre Laurence, Clemenson Alix, Dalac Sophie, Lepage Côme, Chapusot Caroline, Jacquot Caroline, Schiappa Renaud, Lebrun Marine
Department of Genetics, Hôpital Nord, CHU Saint Etienne, 42055 Saint-Etienne Cedex 2, France.
Department of Central Anatomy and Pathological Cytology, Edouard Herriot Hospital, Hospices Civils de Lyon, 69437 Lyon Cedex 3, France.
Hered Cancer Clin Pract. 2017 May 12;15:6. doi: 10.1186/s13053-017-0066-9. eCollection 2017.
The tumor spectrum in the Lynch syndrome is well defined, comprising an increased risk of developing colonic and extracolonic malignancies. Muir-Torre syndrome is a variant with a higher risk of skin disease. Patients have been described carrying mutations in the mismatch repair genes and presenting tumors with unusual histology or affected organ not part of the Lynch syndrome spectrum. Hence, the real link between Lynch syndrome, or Muir-Torre syndrome, and these tumors remains difficult to assess.
We present the case of a 45-year-old-woman, diagnosed with breast cancer at 39 years of age and skin squamous cell carcinoma (SCC) at 41 years of age, without personal history of colorectal cancer. The microsatellite instability analysis performed on the skin SCC showed a low-level of microsatellite instability (MSI-Low). The immunohistochemical expression analysis of the four DNA mismatch repair proteins MLH1, MSH2, MSH6 and PMS2 showed a partial loss of the expression of MSH2 and MSH6 proteins. Germline deletion was found in gene (c.1277-? _1661 + ?del), exon 8 to 10. Then, at 45 years of age, she presented hyperplastic polyps of the colon and a sebaceous adenoma.
Squamous cell carcinomas have been described in Lynch syndrome and Muir-Torre syndrome in two studies and two case reports. This new case further supports a possible relationship between Lynch syndrome and squamous cell carcinoma.
林奇综合征中的肿瘤谱已明确界定，包括患结肠和结肠外恶性肿瘤风险增加。穆尔-托综合征是一种皮肤疾病风险更高的变异型。已描述携带错配修复基因突变且出现组织学异常或受累器官不属于林奇综合征谱的肿瘤患者。因此，林奇综合征或穆尔-托综合征与这些肿瘤之间的真正联系仍难以评估。
我们报告一例45岁女性病例，该患者39岁时被诊断为乳腺癌，41岁时被诊断为皮肤鳞状细胞癌（SCC），无结直肠癌个人史。对皮肤SCC进行的微卫星不稳定性分析显示微卫星不稳定性水平较低（微卫星低度不稳定，MSI-Low）。对四种DNA错配修复蛋白MLH1、MSH2、MSH6和PMS2的免疫组化表达分析显示MSH2和MSH6蛋白表达部分缺失。在基因（c.1277-？_1661 + ？del）外显子8至10中发现胚系缺失。然后，在45岁时，她出现了结肠增生性息肉和皮脂腺腺瘤。
两项研究和两篇病例报告中均描述了林奇综合征和穆尔-托综合征中的鳞状细胞癌。这一新病例进一步支持了林奇综合征与鳞状细胞癌之间可能存在的关联。
