A 5-y-old, male degu (Octodon degus) was presented with a subcutaneous mass in the ventral aspect of the cervical area. The mass was removed surgically. Histologically, the mass was a densely cellular, expansile neoplasm, with compression of thymic tissue to the periphery. The neoplasm consisted of solid sheets of polygonal cells, mixed with fewer small lymphocytes. Rare Hassall bodies were scattered throughout the mass. Polygonal cells were positive for anti-keratin/cytokeratin AE1/AE3 antibody, and small lymphocytes were positive for anti-CD3 antibody. The histopathologic and immunohistochemical findings were consistent with a thymoma. In addition, an autopsy revealed myxosarcoma of the right thoracic wall with metastasis to the lung. To our knowledge, thymoma originating from the cervical component of the thymus has not been documented previously in a rodent species.

一只 5 岁的雄性八齿犬 ( Octodon degus) 在颈部区域的腹侧出现皮下肿块。手术切除肿块。组织学上，肿块是一种细胞密集、可扩张的肿瘤，胸腺组织向周围压迫。肿瘤由实心的多边形细胞片组成，混有少量小淋巴细胞。稀有的哈索尔尸体散落在整个群众中。多角细胞抗角蛋白/细胞角蛋白AE1/AE3抗体阳性，小淋巴细胞抗CD3抗体阳性。组织病理学和免疫组化结果与胸腺瘤一致。此外，尸检显示右胸壁粘液肉瘤并转移至肺。据我们所知，起源于胸腺颈部部分的胸腺瘤以前没有在啮齿动物物种中记录过。