: Peripheral nerve sheath tumors (PNSTs) are heterogeneous tumor groups of peripheral nerves that originate from either Schwann cells or modified Schwann cells, fibroblasts, or perineural cells. In this study, signalment and clinical data such as tumor location and size were evaluated for 15 cases of PNSTs collected from local animal hospitals. The mean age of dogs with malignant PNST was higher than that of dogs with benign PNST. Additionally, the male to female ratio in dogs with PNST was 1 : 4. In dogs with PNST, the primary sites of involvement were the hindlimb, forelimb, around the mammary glands, the neck, and the abdomen. Histiopathologic examination revealed that eight PNSTs were benign and seven were malignant. The tumor cells were composed of loosely to densely arranged interlacing bundles and wavy spindle cells arranged in short bundles, palisading, and whirling. High mitotic figures, local invasion, multifocal necrosis and atypical multinucleated giant cells were observed in malignant PNST cases. All PNSTs showed immunoreactivity for vimentin and S-100. However, only 93.3% and 73.3% were immunoreactive for NSE and GFAP, respectively. Overall, these results indicated that immunohistochemical markers such as vimentin, S-100 and NSE could help confirm the diagnosis of canine PNSTs.

In February 2013, two Korean native goats with circling, dysphagia, sialorrhea, and death were submitted for necropsy to the Jeju Self-Governing Provincial Veterinary Research Institute. Histopathologically, multifocal to confluent micro-abscess composed of neutrophils and macrophages and severe mulifocal perivascular cuffing were observed in pons, medulla oblongata, and cerebellum. Isolated bacteria from the brain sample were Gram-positive coccobacilli and were confirmed as Listeria (L.) monocytogenes by VITEK and PCR analysis. Based on clinical sign, histopathology and bacterial isolation, this case was diagnosed as encephalitic listeriosis. In our best knowledge, this is the first report of encephalitic listeriosis caused by L. monocytogenes in Korean native goats in Jeju.