Shiraishi Junichi, Nomori Hiroaki, Orikasa Hideki, Mori Taisuke, Yamazaki Kazuto
Department of Pathology, Japanese Red Cross Medical Center, 4-1-22 Hiroo, Tokyo 150-8935, Japan.
Virchows Arch. 2006 Aug;449(2):234-7. doi: 10.1007/s00428-006-0218-1. Epub 2006 May 4.
We report a case of type-B3 thymoma manifesting neuroendocrine differentiation. The patient was a 42-year-old woman who complained of shoulder pain but had no symptoms of myasthenia gravis or anemia. The tumor was located in the anterior mediastinum and had directly invaded the pericardium and left lung. Histological examination revealed that the tumor was lobulated by bands of fibrous tissue, perivascular spaces were scattered throughout the tumor, and there were a few intraepithelial lymphocytes. The vast majority of lymphocytes in the perivascular spaces and in the lobulated tumor were immunohistochemically positive for TdT, MIC2, and CD1a. The majority of tumor cells were polygonal and medium or large in size. The tumor cells were weakly positive for synaptophysin, chromogranin A, CD56, and NSE. Small nests of small, relatively uniform polygonal cells were observed facing the fibrous bands. These cells resembled the cells of carcinoid tumors and were strongly positive for NSE, synaptophysin, chromogranin A, and CD56. Ultrastructurally, sparse dense-core granules were observed in the cytoplasm of a few tumor cells. This is a unique case of thymoma with neuroendocrine differentiation, and to the best of our knowledge this is the first such case ever reported.
我们报告一例表现为神经内分泌分化的B3型胸腺瘤病例。患者为一名42岁女性，主诉肩部疼痛，但无重症肌无力或贫血症状。肿瘤位于前纵隔，已直接侵犯心包和左肺。组织学检查显示，肿瘤被纤维组织带分隔成小叶状，血管周围间隙散在分布于整个肿瘤内，并有少量上皮内淋巴细胞。血管周围间隙和小叶状肿瘤中的绝大多数淋巴细胞免疫组化检测显示TdT、MIC2和CD1a呈阳性。大多数肿瘤细胞呈多边形，大小为中等或大。肿瘤细胞突触素、嗜铬粒蛋白A、CD56和神经元特异性烯醇化酶呈弱阳性。在纤维带附近观察到小巢状相对均匀的小多边形细胞。这些细胞类似于类癌肿瘤细胞，神经元特异性烯醇化酶、突触素、嗜铬粒蛋白A和CD56呈强阳性。超微结构观察显示，少数肿瘤细胞的细胞质中有稀疏的致密核心颗粒。这是一例具有神经内分泌分化的独特胸腺瘤病例，据我们所知，这是首例此类病例报告。
