Tumor maligno de bainha de nervo periférico em um felino - relato de caso

Abstract

The malignant peripheral nerve sheath tumor, or malignant Schwannoma is an uncommon tumor in felines, derived from the Schwann cell with high cellular atypia that infiltrates to the adjacent tissues. The most usual location for this tumor is the skin or the subcutaneous, where are observed poorly defined masses that are well adhered to the soft adjacent tissues. Cytology is a useful tool for characterizing a spindle cell tumor with various criteria of malignancy, helping the physician to choose the appropriate treatment. For this kind of tumors is required wide surgical excision. Histopathological examination is required for a definitive diagnosis, and in most cases is necessary some immunohistochemical techniques, such as vimentin. This paper describes a case of malignant peripheral nerve sheath tumor in a feline diagnosed by fine needle aspiration cytology of the tumor, followed by surgical excision of the tumor, histopathological analysis and immunohistochemistry. The morphologic diagnosis of mesenchymal neoplasm confirms the suspicion raised by cytology and together were performed the immunohistochemical panel of vimentin, GFAP, Von Willebrand factor and cytokeratin. The only marker that showed positive result was vimentin, confirming the origin of the tumor of mesenchymal cells. The animal showed no local recurrence or metastases. It is concluded that with the convenience and rapidity of diagnosis by aspiration cytology was possible to perform surgical excision and effective therapy for the removal of neoplastic cells, without the animal have to pass by prior anesthesia, thereby reducing the risk of both anesthetic and surgical complications.