Malignant peripheral nerve sheath tumour in a dog presenting as a pseudo aneurysm of the left jugular vein: a case report

The authors report an autopsy case of a malignant peripheral nerve sheath tumour in a 9-year-old female Akito-ino dog, presenting as a pseudo aneurysm of the left jugular vein. Signs and symptoms included swelling of the neck and legs, dyspnea, malaise and weight loss. Post-mortem examination revealed a tumour mass (8 x 6, 5 x 6 cm), localized to the left paravertebrally, and on the level of C7 to T2 vertebral bodies; additional masses were observed in both lungs, heart and left kidney. On the basis of necropsy, histological findings and immunophenotype, the tumour was classsified as a malignant peripheral nerve sheath tumour. Immunohistochemistry especially positivity for S-100 protein can be helpful in distinguishing this type of neoplasm from other malignancies with similar morphologies.