Extranodal Lymphoma with Peripheral Nervous System Involvement in a Dog

Abstract

An 8-year-old neutered female Cavalier King Charles Spaniel was evaluated for progressing right forelimb lameness. Upon magnetic resonance imaging, the right-sided radius nerves and the caudal brachial plexus were swelled. The histological and molecular biological diagnosis of partial the C8 spinal nerve was T-cell lymphoma. Co-administration of lomustine and irradiation was started. However, this therapy was ineffective. At necropsy, neoplastic tissues were seen extending into the subarachnoid space of the spinal cord, the liver, pancreas and kidneys as gross findings. A large mass was also identified occupying the caudal thorax. Histologic findings included infiltration in these organs and mass by neoplastic lymphocytes. To date, involvement of peripheral nerves (neurolymphomatosis) is rarely reported in veterinary species.