Intercontinental collaborative experience with abdominal, retroperitoneal and pelvic schwannomas

Abstract

Background Schwannomas are rare tumours that pose a significant management challenge in the abdomen, retroperitoneum and pelvis. No data are available to inform management strategy. Methods A collaborative international cohort study, across specialist sarcoma units, was conducted to include adults presenting between 2000 and 2017 with histopathologically confirmed schwannomas within the abdomen, retroperitoneum or pelvis. Results Of 485 patients across 12 centres, 38 (7·8 per cent) were discharged without follow‐up, 199 (41·0 per cent) underwent early resection and 248 (51·1 per cent) had radiological monitoring. Of these 248 patients, 96 (38·7 per cent) eventually had surgery, giving an overall resection rate of 60·8 per cent (295 of 485). At baseline, median tumour volume was 90·1 (i.q.r. 26·5–262·0) cm3. The estimated growth rate was 10·5 (95 per cent c.i. 9·4 to 11·6) per cent per year, and was consistent in the short term (within 2 years of diagnosis) and long term (beyond 2 years) (ρ = 0·405, P = 0·021). A decision to operate was more common in symptomatic patients (P < 0·001) and for rapidly growing tumours (growth rate more than 20 per cent per year) (P = 0·025). R0/R1 resection was achieved in 91·6 per cent of patients (263 of 287). Kaplan–Meier long‐term recurrence rates after R0/R1 resection were 2·3 and 6·7 per cent at 3 and 5 years respectively. Conclusion Specific recommendations include: indications for early surgery, prediction of growth from radiological monitoring, promotion of selective submacroscopic resection and cessation of postoperative imaging surveillance.

Integrated Neurosurgical Management of Retroperitoneal Benign Nerve Sheath Tumors

“…The retroperitoneal space is an uncommon location for PNST; in particular, retroperitoneal schwannomas and neurofibromas represent less than 3–6% of all PNST [ 2 , 4 ] and 1–15% of primary retroperitoneal tumors [ 3 , 21 , 22 ]. Due to the compliance of the retroperitoneum, they often grow to giant sizes before becoming clinically evident, usually in the 5–6th decade of life [ 8 ] ( Table 1 and Table 2 ). Still, diagnosis is incidental in about half of cases [ 8 ].…”

“…As evident from the literature, these tumors are often treated by surgeons who are familiar with the abdominal district but have limited experience in nerve-sparing microsurgical techniques. Therefore, in many publications, the focus is put on the radicality of resection rather than the preservation of neurological function [ 5 , 6 , 7 ] and neurological outcomes are under-reported [ 5 , 8 ].…”

Robotic Nerve Sheath Tumor Resection With Intraoperative Neuromonitoring: Case Series and Systematic Review

“…Tumors were more likely to arise from the right (67.9%) than from the left (32.1%). Based on available data, when compared with traditional open resection, robot-assisted surgery was associated with lower average blood loss (87.4 vs 3889 mL), 18 shorter hospitalization (3.4 vs 6 d), 19 and shorter operative time (145 vs 434 min). 20 One patient experienced a temporary motor neurological deficit after resection of an obturator schwannoma, and no patients experienced significant permanent neurological deficits.…”

Interdisciplinary approach allows minimally invasive, nerve-sparing removal of retroperitoneal peripheral nerve sheath tumors

“…There are two main strategies in dealing with histologyproven PNST, specifically, en bloc resection with or without margin resection and radiological monitoring. A recent retrospective multicenter study studied growth dynamics of 248 retroperitoneal PNST, which were initially subjected to radiological monitoring [4]. The average annual growth rate was 10.5%, prompting the authors to recommend early surgery in cases of symptomatic tumor, diagnostic uncertainty, and existing evidence of rapid expansion or patient preference after adequate counseling.…”

“…Complete excision is the therapy of choice but considerable controversy exists over timing of surgery and negative soft tissue margins [4,5]. Aggressive en bloc resection to avoid local tumor recurrence and/or malignant transformation is recommended by national guidelines, such as the German guidelines for malignant soft tissue tumors.…”