Department of Pathology and Translational Genomics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
Pathol Int. 2020 Jun;70(6):364-369. doi: 10.1111/pin.12926. Epub 2020 Apr 5.
A 36-year-old man was admitted to hospital for a right thyroid nodule incidentally discovered on a chest computed tomography scan for a rib fracture. He had no history of radiation to the head and neck, no known family history of endocrine disease, and no medical or surgical history. A 17 × 10 mm, well-demarcated, multinodular, whitish nodule with neither necrosis nor hemorrhage was found in the right thyroid. Microscopically, the tumor consisted of epithelial cell nests with oval, plasmacytoid or polygonal cells with speckled chromatin, inconspicuous nucleoli and granular cytoplasm. The surrounding stroma showed amyloid deposition and prominent spindle cell proliferation with myxoid substance. Epithelial cell nests showed an immunoreactive pattern for typical medullary thyroid carcinoma (MTC), and the spindle cell stroma showed nuclear expression of beta-catenin. This may be the first report on histopathologic findings of MTC with desmoid-type fibromatosis. Further studies are necessary to discover the clinicopathologic characteristics and pathogenesis of this rare type of tumor.
一位 36 岁男性因肋骨骨折行胸部 CT 扫描时偶然发现右侧甲状腺结节而入院。他无头颈部放射治疗史，无内分泌疾病家族史，也无内科或外科病史。在右侧甲状腺发现一个 17×10mm、边界清楚、多结节、灰白色结节，既无坏死也无出血。显微镜下，肿瘤由上皮细胞巢组成，具有卵圆形、浆细胞样或多边形细胞，染色质呈斑点状，核仁不明显，细胞质颗粒状。周围基质有淀粉样物质沉积和明显的梭形细胞增生。上皮细胞巢对典型的甲状腺髓样癌（MTC）具有免疫反应性，梭形细胞基质β-连环蛋白核表达阳性。这可能是首例报道的具有纤维瘤病样特征的 MTC 的组织病理学发现。需要进一步研究以发现这种罕见类型肿瘤的临床病理特征和发病机制。
