Department of Pathology, Saitama International Medical Center, Saitama Medical University, Saitama, Japan.
Department of Diagnostic Pathology, Saitama Medical University, Saitama, Japan.
Pathol Int. 2024 Apr;74(4):227-233. doi: 10.1111/pin.13420. Epub 2024 Mar 15.
Carcinoma showing thymus-like elements (CASTLE) is a rare tumor that commonly occurs in the thyroid gland. Extrathyroidal CASTLE is rarer, and only 11 cases of CASTLE of major salivary glands have been reported to date. We report the first case of amyloid deposition in parotid CASTLE. A 63-year-old man presented with a slowly growing mass in the left parotid region. Computed tomography revealed an approximately 28 × 23 mm mass lesion in the left parotid gland, and squamous cell carcinoma was suspected on biopsy. The patient underwent a parotidectomy with neck dissection. Morphologically, the tumor cells were squamoid and formed nests with lymphoid infiltration. Immunohistochemically, the tumor cells exhibited immunoreactivity for CD5, CD117/c-kit and Bcl-2, p40, and CK5 but not for p16. We diagnosed the tumor as parotid CASTLE. Amyloid deposition was also observed in the primary tumor and metastatic lymph node lesions, which were immunoreactive for cytokeratin 5. Tumor cytokeratin-derived amyloid deposition may be one of characteristics of parotid CASTLE.
癌，胸腺上皮样成分（CASTLE）是一种罕见的肿瘤，常见于甲状腺。甲状腺外 CASTLE 更为罕见，迄今为止仅报道了 11 例涎腺 CASTLE。我们报告首例腮腺 CASTLE 中淀粉样物质沉积。一名 63 岁男性因左侧腮腺区缓慢生长的肿块就诊。计算机断层扫描显示左侧腮腺有一个约 28×23mm 的肿块病变，活检提示鳞状细胞癌。患者接受了腮腺切除术和颈部清扫术。形态学上，肿瘤细胞呈鳞状，形成巢状结构伴淋巴样浸润。免疫组化显示肿瘤细胞表达 CD5、CD117/c-kit 和 Bcl-2、p40、CK5，但不表达 p16。我们诊断为腮腺 CASTLE。原发肿瘤和转移淋巴结病变也观察到淀粉样物质沉积，对细胞角蛋白 5 呈免疫反应性。肿瘤细胞角蛋白衍生的淀粉样物质沉积可能是腮腺 CASTLE 的特征之一。
