Tavasoli Abbas, Golshahi Hannaneh, Rad Maryam Nobakht, Taymouri Afra
Department of Pathology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
Asian Pac J Trop Biomed. 2013 May;3(5):413-5. doi: 10.1016/S2221-1691(13)60086-6.
Trichoepitheliomas are benign follicular appendage tumors with differentiation to all three segments of the hair follicle. A 2 years old female domestic short hair cat presented with a mass on the tail. The mass was surgically excised and for histopathologic and immunohistochemical studies, was sent to Department of Pathology. Histologically, the tumor was encapsulated and consisted of many islands of follicular epithelium and also cysts structures which varied in size and shape. The cells of epithelium islands were round to oval and had variable amounts of slightly, eosinophilic cytoplasm and euchromatic nuclei. The cystic structures were lined by a complex layer of squamous epithelium. Often, cells under went an abrupt transition between basal layers and keratinization without the development of a granular cell layer. No tendency of malignancy was seen in this case. According to mentioned characteristics, trichoepithelioma was diagnosed. By immunohistochemical study it was confirmed that this tumor had epithelial origin because squamous tumor cells reacted with the pan-cytokeratin antibody. The expression of β-catenin was predominately cytoplasmic and also together with numerous positive nuclei but membranous expression was inconsistenet. Distribution of neoplastic cells with β-catenin expression was more than 75% and labeling intensity was strong in both cytoplasm and nuclei. According to author's knowledge, this is the first report of trichoepithelioma in cat in Iran and also investigation of β-catenin expression in feline trichoepithelioma in veterinary literature.
毛发上皮瘤是一种良性毛囊附属器肿瘤，可分化为毛囊的所有三个部分。一只2岁的雌性家养短毛猫尾巴上出现了一个肿块。该肿块被手术切除，并送往病理科进行组织病理学和免疫组织化学研究。组织学上，肿瘤有包膜，由许多毛囊上皮岛以及大小和形状各异的囊肿结构组成。上皮岛的细胞呈圆形至椭圆形，有数量不等的轻度嗜酸性细胞质和常染色质核。囊性结构内衬一层复层鳞状上皮。通常，细胞在基底层之间突然转变并角化，而不形成颗粒细胞层。该病例未发现恶性倾向。根据上述特征，诊断为毛发上皮瘤。通过免疫组织化学研究证实，该肿瘤起源于上皮，因为鳞状肿瘤细胞与全细胞角蛋白抗体发生反应。β-连环蛋白的表达主要在细胞质中，也有许多阳性细胞核，但膜表达不一致。β-连环蛋白表达的肿瘤细胞分布超过75%，细胞质和细胞核中的标记强度均较强。据作者所知，这是伊朗猫毛发上皮瘤的首次报告，也是兽医文献中对猫毛发上皮瘤中β-连环蛋白表达的研究。
