Dorfman D M, Shahsafaei A, Miyauchi A
Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115, USA.
Histopathology. 1998 Feb;32(2):104-9. doi: 10.1046/j.1365-2559.1998.00318.x.
Cases of intrathyroidal epithelial thymoma (ITET)/carcinoma showing thymus-like differentiation (CASTLE) were examined for CD5 immunoreactivity, a feature of true thymic carcinoma, but not other thymic epithelial neoplasms or carcinomas of other sites. ITET/CASTLE, a rare, low-grade malignant neoplasm arising within the thyroid gland which resembles lymphoepithelioma-like and squamous cell carcinoma of the thymus, is postulated to arise from remnants of branchial pouch capable of thymic differentiation, but thymic differentiation in this neoplasm remains unproven.
The largest published series of cases of ITET/CASTLE was examined for CD5 immunoreactivity using an anti-CD5 antibody reactive in fixed, paraffin-embedded tissue with microwave antigen retrieval. Neoplastic cells in all five cases of ITET/CASTLE studied were immunoreactive for CD5, including foci of tumour metastatic to lymph node and lung. In contrast, none of five cases of thyroid carcinoma with squamous differentiation was immunoreactive for CD5. A minority of cases of typical thyroid carcinomas showed some weak immunoreactivity for CD5. Other carcinomas of the head and neck were nonimmunoreactive for CD5.
CD5 immunoreactivity in ITET/CASTLE is new evidence in support of thymic differentiation in this neoplasm.
对甲状腺内上皮性胸腺瘤（ITET）/具有胸腺样分化的癌（CASTLE）进行CD5免疫反应性检测，CD5是真正胸腺癌的一个特征，而其他胸腺上皮性肿瘤或其他部位的癌则无此特征。ITET/CASTLE是一种罕见的、低级别恶性肿瘤，发生于甲状腺内，类似于胸腺的淋巴上皮瘤样癌和鳞状细胞癌，据推测起源于具有胸腺分化能力的鳃囊残余，但该肿瘤中的胸腺分化仍未得到证实。
使用在固定、石蜡包埋组织中经微波抗原修复后具有反应性的抗CD5抗体，对已发表的最大系列ITET/CASTLE病例进行CD5免疫反应性检测。在研究的所有5例ITET/CASTLE病例中，肿瘤细胞对CD5呈免疫反应性，包括转移至淋巴结和肺的肿瘤灶。相比之下，5例具有鳞状分化的甲状腺癌病例均对CD5无免疫反应性。少数典型甲状腺癌病例对CD5显示出一些弱阳性反应。其他头颈部癌对CD5无免疫反应性。
ITET/CASTLE中的CD5免疫反应性是支持该肿瘤胸腺分化的新证据。
