Neurofibromas are benign peripheral nerve sheath tumors that can originate from several elements of peripheral nerves, including axons, Schwann cells, endoneurial fibroblasts, and perineurial cells. The occurrence of a solitary neurofibroma in the external nose, especially that isolated in the nasal columella, is extremely rare. To the best of our knowledge, only 4 cases of solitary neurofibromas in the external nose have been reported in the English literature: on the nasal dorsum, tip, and pyriform aperture, all originating from the trigeminal nerve. We report the first case of a solitary neurofibroma isolated in the nasal columella, which we found in an otherwise healthy 42-year-old man. We completely resected this tumor with a negative resection margin and performed reconstruction with a bilateral spreader graft and caudal septal extension graft using autologous septal cartilage. The postoperative course was successful in both cosmetic and functional results, with no sensory changes at the 1-year follow-up. Surgical treatment for this lesion was challenging due to the cosmetically obvious location and high rate of recurrence. A review of the literature highlights the clinical and histological characteristics, differential diagnosis, and management of solitary neurofibroma of the external nose.

With a rise in total joint replacement and bone tumor surgeries, complications such as osteolysis increasingly occur. Osteolysis can promote bone cysts to form, which reduces bone density and can delay the recovery process by causing fractures [1]. To prevent these fractures, bone cysts are often surgically removed. Conventional bone cyst surgery requires a large incision to gain access to the entire lesion. Through this access window, the cyst is removed using a curet. The inside of the bone is cleaned by following suction and irrigation before it is injected with a drug to promote bone regeneration [2]. The large access window for reaching the lesion may weaken the bone and can be the cause of additional fractures, further delaying the patient’s recovery. Preventative measures such as internal plate fixation also require additional scans and expose the patient to more radiation. The da Vinci Surgical System (da VinciTM Surgical System, Intuitive Surgical Inc, Sunnyvale, CA, USA) is used for minimally invasive surgery on soft tissue. Due to the limited bending and drilling functions, the robot is not applicable to the lesion inside bone. Various continuum robots [3][4] have been developed to overcome this limitation. However, the developed robots have difficulty removing hard, fibrous membrane inside the lesion because of their insufficient rigidity. In this study, we propose a robotic compliant joint based endoscopic surgery system for minimally invasive bone cyst surgery. The proposed system includes a flexible bone drilling instrument with high rigidity which removes the bone cyst, and a roboticized commercial flexible endoscope to provide visual feedback as well as suction and irrigation to clean the lesion. An intuitive control device with auto-rotation display is integrated. Several experiments in which simulated lesions have been removed from cow femurs have been performed to evaluate the system.