Simple SummarySurgery for retroperitoneal benign nerve sheath tumors (PNST) is often conducted without microsurgical techniques, as evident from the literature. However, this is associated with a risk of permanent postoperative neurological deficits when lesions arise from relevant retroperitoneal nerve trunks. Among the papers describing micro/neurosurgical approaches to such tumors, only a few report more than five patients. Here, we present our interdisciplinary approach to retroperitoneal PNST in a series of 15 benign retroperitoneal tumors arising from major lumbosacral nerve trunks. The combination of expertise from both neurosurgeons and abdominal surgeons led to good neurological and oncological outcomes. Our data provide further confirmation that such an interdisciplinary approach is the optimal strategy to manage benign retroperitoneal nerve sheet tumors.AbstractPeripheral nerve sheath tumors (PNST) of the retroperitoneum are rare and are often treated by general surgeons dealing with retroperitoneal cancers. However, resection without the correct microsurgical technique can cause permanent neurological deficits and pain. Here, we discuss our interdisciplinary approach based on the integration of expertise from neurosurgery and abdominal surgery, allowing for both safe exposure and nerve-sparing microsurgical resection of these lesions. We present a series of 15 patients who underwent resection of benign retroperitoneal or pelvic PNST at our institution. The mean age of patients was 48.4 years; 67% were female. Tumors were 14 schwannomas and 1 neurofibroma. Eight patients (53%) reported neurologic symptoms preoperatively. The rate of complete resection was 87% (n = 13); all symptomatic patients showed improvement of their preoperative symptoms. There were no postoperative motor deficits; one patient (7%) developed a permanent sensory deficit. At a mean postoperative follow-up of 31 months, we observed no recurrences. To our best knowledge, this is the second-largest series of benign retroperitoneal PNST consistently managed with microsurgical techniques. Our experience confirms that interdisciplinary management allows for safe treatment of these tumors with good neurological and oncological outcomes.