Jaggard M K J, MacRae C, Ifeacho S, Robinson S, Tolley N S
Department of Otolaryngology, St Mary's Hospital, London, UK.
J Laryngol Otol. 2009 Jul;123(7):796-800. doi: 10.1017/S0022215108003472. Epub 2008 Sep 4.
We report a case of familial medullary thyroid carcinoma in an 87-year-old woman, despite the patient having a high-risk codon 620 mutation.
Medline and PubMed were searched for cases and literature reviews relating to the following keywords: 'codon 620', 'medullary thyroid carcinoma', 'multiple endocrine neoplasia' and 'RET proto-oncogene'.
We report the case of an 87-year-old woman who presented with a goitre, later identified as medullary thyroid carcinoma. Genetic analysis revealed a RET proto-oncogene codon 620 mutation. Genetic testing has revolutionised the management of medullary thyroid carcinoma. The genetic basis of hereditary medullary thyroid carcinoma lies with the RET proto-oncogene. Several disease-causing mutations of this gene have been identified and their clinical prognosis described. The penetrance of these mutations is high; as such, carriers progress to develop medullary thyroid carcinoma at a young age. Mutations at the codon 620 position are classified as high-risk for early development of medullary thyroid carcinoma; thus, the current recommendation is for prophylactic thyroidectomy at five years of age.
In this case, the progress of hereditary medullary thyroid carcinoma was unique, considering the late presentation of medullary thyroid carcinoma despite the presence of the high-risk RET proto-oncogene codon 620 mutation. The authors wish to highlight the importance of this case, as it may present a counter-argument to the current recommendations for early, prophylactic thyroidectomy in codon 620 mutation carriers in order to prevent early development of medullary thyroid carcinoma.
我们报告一例87岁女性家族性甲状腺髓样癌病例，尽管该患者存在高危的密码子620突变。
在Medline和PubMed上搜索与以下关键词相关的病例和文献综述：“密码子620”、“甲状腺髓样癌”、“多发性内分泌腺瘤病”和“RET原癌基因”。
我们报告了一例87岁女性病例，该患者最初表现为甲状腺肿大，后来被确诊为甲状腺髓样癌。基因分析显示存在RET原癌基因密码子620突变。基因检测彻底改变了甲状腺髓样癌的治疗方式。遗传性甲状腺髓样癌的遗传基础在于RET原癌基因。已经鉴定出该基因的几种致病突变，并描述了它们的临床预后。这些突变的外显率很高；因此，携带者在年轻时就会发展为甲状腺髓样癌。密码子620位置的突变被归类为甲状腺髓样癌早期发展的高危突变；因此，目前的建议是在5岁时进行预防性甲状腺切除术。
在本病例中，遗传性甲状腺髓样癌的进展具有独特性，因为尽管存在高危的RET原癌基因密码子620突变，但甲状腺髓样癌的出现较晚。作者希望强调该病例的重要性，因为它可能对目前关于对密码子620突变携带者进行早期预防性甲状腺切除术以预防甲状腺髓样癌早期发展的建议提出反驳。
