Sobral-Leite Marcelo, da Silva Jesse Lopes, Pimenta-Inada Haynna Kimie, Mendes Boisson Andrea Sobral, Romeiro Priscila de Almeida, Soares Parago Fernando Mallet, Valadão da Silva Marcus Vinicius M, de Melo Andreia Cristina
Division of Molecular Pathology, Netherlands Cancer Institute, Amsterdam, Netherlands.
Pharmacology Program, Brazilian National Cancer Institute, Rio de Janeiro, RJ, Brazil.
Am J Case Rep. 2021 Mar 6;22:e929887. doi: 10.12659/AJCR.929887.
BACKGROUND Gastrointestinal stromal tumors (GISTs) are rare mesenchymal cancers that affect the gastrointestinal tract and are most often located in the stomach and proximal small intestine. The most common molecular genetic abnormalities underlying GIST carcinogenesis are mutations in the tyrosine kinase gene (KIT) and in the platelet-derived growth factor receptor alpha (PDGFRA) gene. To the best of our knowledge, no cases have been reported so far of synchronous diagnosis of GIST in 2 monozygotic twins presenting with clinical and morphological features of sporadic disease. CASE REPORT This report presents the cases of 2 monozygotic twin sisters who were diagnosed with GIST at the same age and who had different KIT exon 11 tumor mutational statuses. In the current report, the screening examination that led to early detection of GIST in one of the sisters was not motivated by any symptom, but by a GIST diagnosis in her twin a few days before. The literature was reviewed for pathological and molecular features associated with prognosis and treatment response. Furthermore, we identified identical genotypes of KIT and PDGFRA polymorphisms in the DNA of both tumors that might be present in the germline DNA. The present case supports the implementation of specific cancer screening in the context of monozygotic twins, regardless of identification of the genetic components involved. CONCLUSIONS Our report suggests that monozygotic twins with GIST can have different mutational statuses for KIT and PDGFRA. Referral for special screening should be considered for individuals who have a monozygotic twin diagnosed with cancer.
背景 胃肠道间质瘤（GIST）是一种罕见的间叶组织癌症，累及胃肠道，最常发生于胃和近端小肠。GIST致癌过程中最常见的分子遗传学异常是酪氨酸激酶基因（KIT）和血小板衍生生长因子受体α（PDGFRA）基因的突变。据我们所知，目前尚无关于2例单卵双胞胎同时诊断为GIST且表现为散发性疾病临床和形态学特征的病例报道。病例报告 本报告介绍了2例单卵双胞胎姐妹的病例，她们在相同年龄被诊断为GIST，但KIT外显子11肿瘤突变状态不同。在本报告中，导致其中一名姐妹早期发现GIST的筛查检查并非由任何症状引起，而是由于其双胞胎姐妹几天前被诊断为GIST。我们查阅了与预后和治疗反应相关的病理和分子特征的文献。此外，我们在两个肿瘤的DNA中鉴定出KIT和PDGFRA多态性的相同基因型，这些基因型可能存在于种系DNA中。本病例支持在单卵双胞胎中实施特定的癌症筛查，无论是否鉴定出相关的遗传成分。结论 我们的报告表明，患有GIST的单卵双胞胎在KIT和PDGFRA方面可能具有不同的突变状态。对于有单卵双胞胎被诊断患有癌症的个体，应考虑进行特殊筛查。
