背景:平滑肌肉瘤是一种罕见的平滑肌源性恶性肿瘤,占所有软组织肉瘤的10-20%。原发性结肠和直肠肉瘤占所有大肠恶性肿瘤的<0.1%。在Li-Fraumeni综合征中,肉瘤是第二常见的癌症(25%)。Li-Fraumeni综合征是一种遗传性疾病,具有多种恶性肿瘤的家族易感性。该综合征具有常染色体显性遗传模式和以种系TP53突变为特征的高外显率。有癌症史的患者如果不符合Li-Fraumeni综合征的所有“经典”标准,则被认为患有Li-Fraumeni样综合征。据我们所知,本文是首次报道以直肠平滑肌肉瘤为Li-Fraumeni样综合征的初始表型表现的患者。作者还提出了文献综述。
方法:一名67岁的巴西妇女因直肠平滑肌肉瘤行直肠乙状结肠前切除术和全子宫切除术。她随后患上了癌病,并在手术后2年死亡。她的家族病史包括一个32岁死于乳腺癌的女儿,一名孙女在6岁时被诊断出患有肾上腺皮质癌,两名兄弟姐妹死于前列腺癌。进行了遗传研究以鉴定Li-Fraumeni综合征的致病变体。从外周血白细胞中提取的DNA,分析限制性片段长度多态性以搜索TP53基因中的突变.DNA测序鉴定了TP53外显子10中的种系致病变体p.R337H杂合。患者被分类为患有Li-Fraumeni样综合征。
结论:在直肠平滑肌肉瘤患者中,建议调查癌症家族史并进行遗传学研究以筛查Li-Fraumeni综合征.
BACKGROUND: Leiomyosarcoma is a rare malignant tumor of smooth muscle origin and represents 10-20% of all soft tissue sarcomas. Primary colon and rectal sarcomas constitute < 0.1% of all large bowel malignancies. In Li-Fraumeni syndrome, sarcomas are the second most frequent cancer (25%). Li-Fraumeni syndrome is a genetic disease with a familial predisposition to multiple malignant neoplasms. This syndrome has an autosomal dominant pattern of inheritance and high penetrance characterized by germline TP53 mutations. Patients with a history of cancer who do not meet all the \"classic\" criteria for Li-Fraumeni syndrome are considered to have Li-Fraumeni-like syndrome. To the best of our knowledge, this article is the first report of a patient with rectal leiomyosarcoma as the initial phenotypic manifestation of Li-Fraumeni-like syndrome. The authors also present a literature
review.
METHODS: A 67-year-old Brazilian woman underwent anterior rectosigmoidectomy and panhysterectomy secondary to rectal leiomyosarcoma. She subsequently developed carcinomatosis and died 2 years after the operation. Her family medical history consisted of a daughter who died at 32 years of age from breast cancer, a granddaughter diagnosed with adrenocortical carcinoma at 6 years of age and two siblings who died from prostate cancer. A genetic study was carried out to identify a pathogenic variant of Li-Fraumeni syndrome. In the DNA extracted from the peripheral blood leukocyte, restriction fragment length polymorphism was analyzed to search for mutations in the TP53 gene. The DNA sequencing identified the germline pathogenic variant p. R337H heterozygous in exon 10 of TP53. The patient was classified as having Li-Fraumeni-like syndrome.
CONCLUSIONS: In patients with rectal leiomyosarcoma, it is advisable to investigate the family history of cancer and perform genetic studies to screen for Li-Fraumeni syndrome.