张刚 陈懿 徐琰

[摘要] 临床工作中，患者因血清癌胚抗原（CEA）水平异常升高首次就诊时，在常规检查未见肿瘤征象时，容易漏诊甲状腺髓样癌。PET/CT（正电子发射断层显像/计算机体层扫描）可以为早期定位病灶提供线索。陆军军医大学大坪医院&野战外科研究所收治1例因血清CEA水平异常升高首次就诊的患者，首先对其胃肠道肿瘤行系统检查未见肿瘤征象，进一步行PET/CT检查发现甲状腺占位病变。术后病理证实为甲状腺髓样癌。进一步行RET原癌基因检测提示：p.Cys634Tyr雜合子突变，家系内两名成员携带该基因突变。同时检查发现合并甲状旁腺增生和肾上腺增生。家系患者临床表现可能符合家族遗传性甲状腺髓样癌或多发性内分泌肿瘤2A型。

[关键词] 癌胚抗原；PET/CT；家族遗传性甲状腺髓样癌；RET原癌基因

[中图分类号] R736.1 [文献标识码] A [文章编号] 1673-7210（2018）05（b）-0083-04

Clinical diagnosis and genetic mutation analysis of hereditary medullary thyroid carcinoma with CEA levels abnormal elevation as the initial clinical manifestation

ZHANG Gang CHEN Yi XU Yan

Department of Breast， Thyroid， Research Institute of Surgery， Daping Hospital， the Army Military University， Chongqing 400042， China

[Abstract] In clinical work， patients with abnormal serum CEA （carcino-embryonic antigen） levels increased at first visit， in the conventional examination showed no signs of tumor， easily missed diagnosis of medullary thyroid carcinoma. PET/CT （positron-emission tomography/computer tomography） can provide clues for early localization of lesions. A case of abnormal increase of serum CEA level for the first time treated in Daping Hospital， the Army Military University， first of gastrointestinal tumors for examination had no system signs of tumor， further PET/CT examination revealed thyroid lesions. The postoperative pathology proved to be a thyroid medullary carcinoma. Further RET proto oncogene detection suggested that p.Cys634Tyr heterozygote mutation， two members of the family carrying the gene mutation. Both parathyroid hyperplasia and adrenal hyperplasia were found at the same time. The clinical manifestations of family patients may be in line with familial hereditary medullary thyroid carcinoma or multiple endocrine neoplasm type 2A （Family medullary thyroid carcinom/Multiple endocrine neoplasia type 2A； FMTC/MEN2A）.

[Key words] CEA； Positron-emission tomography/computer tomography； Multiple endocrine neoplasia type 2A； RET protooncogene

血清学肿瘤标志物癌胚抗原（CEA）最常用于监测结直肠癌的发病。临床发现血清异常升高的CEA时，也存在于肺癌、神经内分泌肿瘤、胰腺肿瘤和甲状腺髓样癌等[1-2]。CEA水平异常升高，往往首先就诊于消化内科，无特异临床表现，腹部CT、胃肠镜检查等检查阴性结果时，早期诊断困难[3]。在没有阳性结果时可以考虑PET/CT行全身评估，有时可意外发现甲状腺髓样癌[2]，进而减少漏诊。对于确诊的甲状腺髓样癌，行家系调查，根据成员发病情况可诊断遗传性甲状腺髓样癌，对于家系内直系血缘关系的成员常规推荐行RET原癌基因检测[4-5]，可以较早的发现病情。……