Dettmer M S, Schmitt A, Komminoth P, Perren A
Institut für Pathologie, Universität Bern, Murtenstraße 31, 3008, Bern, Schweiz.
Institut für Pathologie, Stadtspital Triemli, Birmensdorferstraße 497, 8063, Zürich, Schweiz.
Pathologe. 2019 May;40(3):227-234. doi: 10.1007/s00292-019-0613-4.
Poorly differentiated thyroid carcinomas (PDTCs) are a rare subtype of thyroid carcinomas that are biologically situated between well-differentiated papillary/follicular thyroid carcinomas and anaplastic thyroid carcinomas (ATCs).The diagnosis of conventional as well as oncocytic poorly differentiated thyroid carcinoma is difficult and often missed in daily routine. The current WHO criteria to allow the diagnosis of PDTCs are based on the results of a consensus meeting held in Turin in 2006. Even a minor poorly differentiated component of only 10% of a given carcinoma significantly affects patient prognosis and the oncocytic subtype may even have a worse outcome. Immunohistochemistry is not much help and is mostly used to exclude a medullary thyroid carcinoma with calcitonin and to establish a follicular cell of origin via thyroglobulin staining.Due to the concept of stepwise dedifferentiation, there is a vast overlap of different molecular alterations like BRAF, RAS, CTNNB1, TP53 and others between different thyroid carcinoma subtypes. A distinctive molecular tumor profile is therefore currently not available.PDTCs have a unique miRNA signature, which separates them from other thyroid carcinomas.The average relapse free survival is less than one year and about 50% of patients die of the disease. Modern tyrosine kinase inhibitors offer in conjunction with powerful molecular diagnostic new chances in these difficult to treat carcinomas.
低分化甲状腺癌（PDTC）是甲状腺癌的一种罕见亚型，其生物学特性介于高分化乳头状/滤泡状甲状腺癌和未分化甲状腺癌（ATC）之间。常规以及嗜酸性细胞型低分化甲状腺癌的诊断都很困难，在日常诊疗中常常被漏诊。目前世界卫生组织（WHO）用于诊断PDTC的标准是基于2006年在都灵召开的一次共识会议的结果。即使某一特定癌组织中仅10%的微小低分化成分也会显著影响患者预后，而嗜酸性细胞亚型的预后可能更差。免疫组化帮助不大，主要用于通过降钙素排除甲状腺髓样癌，并通过甲状腺球蛋白染色确定起源的滤泡细胞。由于存在逐步去分化的概念，不同甲状腺癌亚型之间在BRAF、RAS、CTNNB1、TP53等不同分子改变方面存在大量重叠。因此，目前尚无独特的分子肿瘤图谱。PDTC具有独特的微小RNA特征，这使其与其他甲状腺癌区分开来。平均无复发生存期不到一年，约50%的患者死于该病。现代酪氨酸激酶抑制剂与强大的分子诊断方法相结合，为这些难以治疗的癌症带来了新的机遇。
