Universiti Sains Malaysia, School of Medical Sciences, Deparment of Pathology, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia.
Malays J Pathol. 2021 Apr;43(1):69-73.
Cancer metastasis to the thyroid gland from non-thyroid sites is a rare presentation in clinical practice. The most frequent primary cancers that metastasise to the thyroid are renal cell carcinoma, followed by colorectal, lung and breast. We report a case of a 64-year-old Malay lady who presented with anterior neck swelling 4 years after an initial diagnosis of uterine leiomyosarcoma. She had undergone a hysterectomy procedure four years ago. Fine needle aspiration cytology of the thyroid mass suggested undifferentiated thyroid carcinoma. After multi-disciplinary discussion, the patient underwent thyroidectomy and the final histopathological diagnosis was metastatic leiomyosarcoma of the thyroid. The diagnosis was aided by an immunohistochemistry panel of positive myogenic markers, negative epithelial markers as well as the previous medical history of uterine leiomyosarcoma. Metastatic leiomyosarcoma of the thyroid may mimic primary undifferentiated (anaplastic) thyroid carcinoma (UTC) with a sarcomatoid pattern, medullary thyroid carcinoma (MTC) with spindle cells morphology and spindle cell tumour with thymus-like differentiation (SETTLE). Hence, a multidisciplinary approach must be practised by pathologists, surgeons and radiologists to consider metastatic lesions of the thyroid gland, especially when a previous history of cancer exists or is suspected.
非甲状腺部位的癌症转移至甲状腺在临床实践中较为罕见。最常转移至甲状腺的原发性癌症是肾细胞癌，其次是结直肠癌、肺癌和乳腺癌。我们报告了 1 例 64 岁马来女性患者的病例，她在最初诊断为子宫平滑肌肉瘤 4 年后出现前颈部肿胀。她在四年前接受了子宫切除术。甲状腺肿块的细针抽吸细胞学检查提示未分化甲状腺癌。经过多学科讨论，患者接受了甲状腺切除术，最终的组织病理学诊断为甲状腺转移性平滑肌肉肉瘤。免疫组织化学阳性肌源性标志物、阴性上皮标志物以及先前的子宫平滑肌肉瘤病史有助于诊断。甲状腺转移性平滑肌肉肉瘤可能类似于原发性未分化（间变性）甲状腺癌（UTC）伴肉瘤样形态、甲状腺髓样癌（MTC）伴梭形细胞形态和胸腺样分化的梭形细胞瘤（SETTLE）。因此，病理学家、外科医生和放射科医生必须采取多学科方法来考虑甲状腺转移病灶，特别是当存在或怀疑先前有癌症病史时。
