Malignant neoplasm of the perineural sheath retrobulbar and intracranial in dog: case report

ABSTRACT Tumors of the perineural sheath are uncommon in domestic animals. We report the case of a 5-year-old female dog with a history of increased volume in the retrobulbar region of the right eye (RE) three weeks ago. The clinical examination revealed a presence of a right retrobulbar neoformation with cranial ocular globe displacement. In the examinations carried out during hospitalization, it was not possible to locate a source and an extension of the neoformation. The animal died of cardiorespiratory arrest and was referred to an autopsy. The macroscopic evaluation revealed a whitish neoformation fixated to the base of the skull in a seal region, with a possible non-III origin of cranial nerves, infiltrating non-encephalon at the height of the hypothalamus, extending caudally towards the brainstem and cranially to the orbit right, compressing RE. Microscopically it consisted of short bundles intertwined or enovelados of spindle cells with discrete to moderate pleomorphism, alternating to areas of multifocal necrosis, compatible with tumor of the perineural sheath. Immunohistochemical examination showed weak marking for S100 and GFAP and positive marking for vimentin, indicating malignancy.

摘要：神经鞘肿瘤（perineural sheath tumor）在家养动物中较为罕见。本研究报告1例5岁雌性犬病例：该犬三周前出现右眼（RE）球后区域体积增大的病史。临床检查可见右侧球后存在新生肿物，伴眼球向颅侧移位。住院期间开展的各项检查均无法明确该新生肿物的起源部位与侵袭范围。该动物因心搏呼吸骤停死亡，随后进行了尸体剖检。大体病理学观察可见一灰白色新生肿物固定于颅底鞍区，推测其起源非第Ⅲ对脑神经，在下丘脑水平浸润非脑组织，向尾侧延伸至脑干，向颅侧延伸至右侧眼眶，压迫右眼（RE）。镜下观察可见交织或包裹的短束状梭形细胞，伴轻度至中度多形性，与多灶性坏死区域交替分布，符合神经鞘肿瘤的病理特征。免疫组织化学检查显示，S100与胶质纤维酸性蛋白（GFAP）呈弱阳性标记，波形蛋白（vimentin）呈阳性标记，提示该肿瘤为恶性。