Asa S L, Dardick I, Van Nostrand A W, Bailey D J, Gullane P J
Department of Pathology, St. Michael's Hospital, Toronto, Ontario, Canada.
Hum Pathol. 1988 Dec;19(12):1463-7. doi: 10.1016/s0046-8177(88)80242-9.
A 51-year-old man presented with a paratracheal tumor. He had undergone resection of a thyroid tumor 15 years previously; at that time, the histologic diagnosis had been anaplastic carcinoma. When the tumor recurred, the presumptive clinical diagnosis was medullary thyroid carcinoma. Histologic examination revealed a poorly differentiated epithelial tumor with immunoreactivity for keratins, carcinoembryonic antigen, and, focally, S-100 protein. The tumor was negative for calcitonin and thyroglobulin. There were scattered lymphocytes and plasma cells. Ultrastructural examination showed elongated epithelial cells with prominent desmosomes and bundles of cytoplasmic tonofilaments but no secretory granules; amyloid was not present ultrastructurally or histochemically. The characteristic ultrastructural and immunocytochemical features and the clinical behavior of this tumor verify the existence of primary thyroid thymoma. This new primary thyroid neoplasm is of clinical importance, considering the more benign behavior of primary thyroid thymoma than of other tumors in the differential diagnosis of this lesion.
一名51岁男性患者出现气管旁肿瘤。他15年前曾接受过甲状腺肿瘤切除术；当时组织学诊断为未分化癌。肿瘤复发时，临床初步诊断为甲状腺髓样癌。组织学检查显示为低分化上皮性肿瘤，对角蛋白、癌胚抗原呈免疫反应，局部对S-100蛋白呈免疫反应。肿瘤降钙素和甲状腺球蛋白阴性。可见散在的淋巴细胞和浆细胞。超微结构检查显示上皮细胞拉长，有明显的桥粒和束状胞质张力丝，但无分泌颗粒；超微结构和组织化学检查均未发现淀粉样物质。该肿瘤的特征性超微结构和免疫细胞化学特征以及临床行为证实了原发性甲状腺胸腺瘤的存在。考虑到原发性甲状腺胸腺瘤在该病变鉴别诊断中比其他肿瘤行为更良性，这种新的原发性甲状腺肿瘤具有临床重要性。
