Peripheral nerve sheath myxoma. Clinicopathological and immunohistochemical study of a morphologically distinctive myxoid peripheral nerve sheath tumor in the forelimb of a cat

Peripheral nerve sheath tumors (PNST) are a class of nervous system tumors which arise in both schwann cells and perineural fibroblasts. Benign and malignant PNSTs are reported to occur in all domestic animals. In cats they represent 3% of all cutaneous and subcutaneous neoplasms. Only in dogs mixoid PNST has been observed generally localized in the fingers. In humans, PNSTs are rare neoplasms, and nerve sheath myxomas are a distinct neoplasia most commonly found in limb extremities.