Central nervous system metastasis of an intradural malignant peripheral nerve sheath tumor in a dog

Abstract

An 8-yr-old French Bulldog was presented with a non-ambulatory  tetraparesis. Magnetic resonance showed an intradurally located mass at the level of the right second cervical nerve root. The mass was surgically  removed and the dog was ambulatory within 4 d. A 10-mo post-surgical imaging follow-up revealed a recurrence of the primary mass and another intradural/intramedullary mass at the level of the first thoracic vertebral body. Overall histological features were suggestive of malignant peripheral nerve sheath tumor (MPNST) for both masses. Immunohistochemistry was
found weak but diffusely positive for S-100 and neurono-specific enolase for both masses. A diagnosis of primary MPNST for the cervical mass and of metastasis for the thoracic mass was made, possibly disseminated via the
subarachnoidal space. To our knowledge, the central nervous system  metastasis of MPNSTs has not previously been reported in dogs. The clinician should be aware that these tumors, albeit rarely, can metastasize to the central nervous system.

Keywords: Central nervous system metastasis, Dog, Malignant peripheral nerve sheath tumor.