Robot-Assisted Nerve-Sparing Excision of a Symptomatic Obturator Nerve Schwannoma: A Case Report

Reports in the literature have presented the feasibility of a minimally invasive resection of retroperitoneal or pelvic schwannomas. However, there are only a few reports in the literature about a robot-assisted nerve-sparing approach towards obturator schwannomas. We present a case of a concomitant excision of a symptomatic obturator nerve schwannoma in a patient undergoing robot-assisted radical prostatectomy with pelvic lymphadenectomy. The patient complained about an ongoing, low-grade sensory dysfunction in the left proximal thigh area, without loss of muscular function. A preoperative pelvic MRI incidentally showed a thickening of the left obturator nerve of about 1 cm. During pelvic lymphadenectomy, the thickening was identified, an axial incision was made to the nerve sheath, and a small tumor mass (9 mm x 5 mm x 3 mm) was excised, thereby decompressing the nerve fibers and simultaneously preserving the continuity of the obturator nerve. The nerve sheath was closed using a 7-0 monofilament suture. Frozen section biopsy that was undertaken during the surgical procedure excluded the presence of a malignancy. There were no intra- or postoperative complications. Postoperatively, the patient described a temporary sensory dysfunction of the left inner-thigh area, which regressed completely. The histopathological result confirmed a benign schwannoma of the obturator nerve. In experienced hands, the robot-assisted approach appears safe and feasible as a technique to excise a schwannoma of the obturator nerve, without the need to proceed to a full nerve resection.