Malignant peripheral nerve sheath tumors in the abdomen and thoracic wall of a juvenile cat

Abstract

An 11-month-old spayed Kinkalow cat (crossbreed of an American curl and a Munchkin) presented with acute vomiting and anorexia. Radiographic and ultrasound examinations revealed two mass lesions: one in the abdominal cavity and one originating from the thoracic wall. Histopathological examination of the mass revealed a malignant peripheral nerve sheath tumor characterized by highly dysplastic and pleomorphic mesenchymal cells that were positive for anti-S100 antibody. The patient underwent surgery, and two tumor lesions were completely resected. However, on day 490, thoracic radiography revealed signs of lung metastasis, and the patient died of presumptive lung metastasis 520 days after the initial evaluation. We found no published clinical reports on malignant peripheral schwannoma in the abdominal cavities of cats at an early age; thus, the case seemed rare. Additionally, only two cases of metastasis of this tumor type have been reported to date. In these reports, tumor cell pleomorphism and multiple mass formations were considered possible causes of the metastasis.