【摘要】 甲状腺混合恶性肿瘤是一类在同一甲状腺内同时存在两种或多种组织学类型的罕见肿瘤。常见类型包括甲状腺乳头状癌（PTC）合并甲状腺髓样癌（MTC）、PTC合并甲状腺滤泡性癌（FTC）、MTC合并FTC，以及分化型甲状腺癌（DTC）合并甲状腺未分化癌（ATC）。不同成分可呈紧密交织、局部分隔或空间独立分布，形成混合瘤、复合瘤或碰撞瘤。发病机制尚不明确，主要假说包括偶然理论、微环境改变理论及干细胞理论。诊断依赖影像学、细针穿刺或粗针穿刺结合免疫组化及基因检测（如BRAF、RET突变），术后病理是确诊金标准。治疗需依据侵袭性最高的成分制定方案，手术为主要手段，常需结合放射性碘治疗、甲状腺激素抑制、靶向或免疫治疗。含MTC成分者需结合降钙素（Ctn）和癌胚抗原（CEA）水平动态监测；含ATC成分者多需综合放化疗及靶向治疗。预后取决于最具恶性成分，PTC-FTC型预后良好，而伴ATC或肉瘤成分者生存率极低。整体而言，甲状腺混合恶性肿瘤临床异质性强，需个体化管理与长期随访。更多还原

【Abstract】 Mixed thyroid malignancies are rare tumors characterized by the coexistence of two or more distinct histological types within the same thyroid gland. Common forms include papillary thyroid carcinoma(PTC) combined with medullary thyroid carcinoma(MTC), PTC combined with follicular thyroid carcinoma(FTC), MTC combined with FTC, and differentiated thyroid carcinoma(DTC) combined with anaplastic thyroid carcinoma(ATC). The components may display tightly interwoven, partially separated, or spatially independent patterns, leading to the formation of mixed tumors, composite tumors, or collision tumors. The underlying pathogenesis remains unclear, with major hypotheses including the incidental theory, microenvironmental alteration theory, and stem cell theory. Diagnosis relies on imaging studies, fine-needle aspiration or core needle biopsy combined with immunohistochemistry and genetic testing(e. g., BRAF, RET mutations), with postoperative pathology serving as the diagnostic gold standard. Treatment strategies should be guided by the most aggressive component. Surgery is the primary modality and is often combined with radioactive iodine therapy, thyroid hormone suppression, targeted therapy, or immunotherapy. Tumors containing an MTC component require dynamic monitoring of serum calcitonin(Ctn) and carcinoembryonic antigen(CEA), whereas those with an ATC component often necessitate multimodal chemoradiotherapy and targeted therapy. Prognosis depends on the most malignant component: PTC-FTC subtypes generally have favorable outcomes, while those involving ATC or sarcomatous components are associated with extremely poor survival. Overall, mixed thyroid malignancies exhibit marked clinical heterogeneity, necessitating individualized management and long-term follow-up.更多还原