RESUMEN
Introduction: Benign peripheral nerve schwannomas are uncommon tumours. Extra cranial schwannomas have also been reported from uncommon and unusual sites including breast, pancreas, and gastrointestinal system. Peripheral nerve schwannomas may pose a problem in clinical diagnosis, however an appropriate diagnostic work-up including thorough history and clinical examination, Ultrasonography, magnetic resonance imaging, fi ne needle aspiration cytology, nerve conduction velocity and electromyography study may all help reaching the correct preoperative diagnosis. Th e important clinical diff erential diagnoses include traumatic neuroma, neurfi bromas, lipoma, cold abscess and muscle hernia. Th e defi nitive treatment of benign peripheral nerve schwannoma is complete enucleation of the tumour mass without damaging the intact nerve fascicles followed by confi rmatory histopathological examination. When there is a doubt on histopathology, a positive Immunohistochemical staining with S100 is helpful in confi rming a diagnosis of schwannoma. Case presentation: We had 40 years female who had a slow growing swelling over the inner aspect of her right elbow for the last one year; this was followed by pain, tingling and numbness over inner one and half fi ngers of her right hand for six months. Tinnels sign was positive over the swelling. Her subsequent clinical examination and investigations including a magnetic resonance imaging was suggestive of a benign growth in her right ulnar nerve in the elbow region. Complete enucleation of the swelling was done from the right ulnar nerve in the elbow region and subsequent histopathological examination confi rmed it to be a benign cellular schwannoma. Patient recovered successfully after the surgery and paresthesia in the distribution of her right ulnar nerve also improved six weeks after surgery. At her last follow-up six months after surgery, the patient was completely asymptomatic and highly satisfi ed with the results of surgery. Conclusion: A correct preoperative diagnosis of peripheral nerve schwannomas is possible, and it can be successfully managed with complete enucleation of tumour mass with satisfactory patient outcomes.