Pathology Department, Centre Hospitalier Lyon-Sud, Hospices Civils de Lyon, Pierre-Bénite, France.
Biochemistry and Molecular Biology Department, Centre Hospitalier Lyon-Sud, Hospices Civils de Lyon, Pierre-Bénite, France.
Virchows Arch. 2020 Oct;477(4):597-601. doi: 10.1007/s00428-020-02807-7. Epub 2020 Apr 1.
Poorly differentiated thyroid carcinoma (PDTC) refers to a malignant tumour that displays an intermediate prognosis between well-differentiated carcinomas and anaplastic thyroid carcinomas (ATC). In the thyroid, pleomorphic giant cells are observed in ATC or in some non-neoplastic thyroid diseases. We described the case of a 43-year-old woman with a 34-mm nodule in her thyroid right lobe. Microscopic examination revealed an encapsulated tumour with a main solid growth pattern and extensive capsular invasion. Multiple images of angioinvasion were observed. There was neither necrosis nor inflammation. Most of the tumour cells were medium-sized and intermingled with pleomorphic giant tumour cells with bizarre features. The immunoprofile (keratins +, TTF1+, Pax 8+) proved their thyroid origin. By NGS, no molecular alteration was identified. The patient was treated by surgery and radioiodine therapy and she has no recurrence after a follow-up of 24 months. Our case meets all the histological criteria of the Turin proposal for PDTC but with pleomorphic giant cells and is very different from ATC according to clinical, histological and immunohistochemical features. Pleomorphic tumour giant cells in thyroid carcinomas could be present in PDTC and do not always represent dedifferentiation and more aggressive carcinoma, thyroid neoplasm.
低分化甲状腺癌（PDTC）是一种恶性肿瘤，其预后介于高分化癌和间变性甲状腺癌（ATC）之间。在甲状腺中，ATC 或某些非肿瘤性甲状腺疾病中可见多形性巨细胞。我们描述了一例 43 岁女性，其甲状腺右叶有一个 34mm 的结节。显微镜检查显示为包膜肿瘤，主要为实性生长模式，广泛侵犯包膜。观察到多处血管侵犯图像。未见坏死或炎症。大多数肿瘤细胞为中等大小，与具有奇异特征的多形性巨细胞瘤细胞混合存在。免疫组化（角蛋白+，TTF1+，Pax8+）证实其甲状腺来源。通过 NGS 未发现分子改变。患者接受了手术和放射性碘治疗，随访 24 个月后无复发。我们的病例符合 PDTC 的都灵提案的所有组织学标准，但有巨细胞，且根据临床、组织学和免疫组化特征，与 ATC 非常不同。甲状腺癌中的多形性肿瘤巨细胞可能存在于 PDTC 中，并不总是代表去分化和侵袭性更强的癌，甲状腺肿瘤。
