Peripheral nerve sheath tumors (PNSTs) represent a spindeloid neoplastic proliferation of the perineural connective tissues. These tumors include schwannomas, neurogenic sarcomas, neurofibromas and neurofibrosarcomas and may affect a wide range of soft tissues including the orbital, adnexal & ocular structures. Clinically, lesions appear as slowly progressive, firm, non-painful swellings of the orbit, fornix or eyelids. Secondary conjunctivitis and/or deviation of the globe may be associated with their development. Canine and feline species of any breed or crossed breed may be affected.