The Role of Pre-Operative Biopsy in Malignant Peripheral Nerve Sheath Tumours: A Review and Retrospective Series with a Management Algorithm from a Single-Center Experience.

Background/Objectives: Peripheral nerve tumours are commonly encountered in clinical practice. Although most are benign, a subset can exhibit aggressive and invasive behaviour, evolving into malignant peripheral nerve sheath tumours (MPNSTs). Due to their rarity and overlapping features with benign lesions, MPNSTs are frequently misdiagnosed during the initial evaluation. Preoperative biopsy may aid in distinguishing malignant from benign lesions. This single-center study aimed to develop and validate a diagnostic algorithm-based on a systematic literature review and institutional case series-to assess the role of preoperative biopsy in the diagnostic workflow. Methods: A systematic review of the literature was conducted in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, covering the period from 1998 to 2024. Additionally, a retrospective case series of patients with peripheral nerve lesions treated at the authors' institution between January 2018 and June 2024 was analysed. Results: Forty-eight articles met the inclusion criteria and were categorized into five key domains: radiological features of MPNSTs, associated risk factors and genetic conditions, the role of preoperative biopsy, use of radiotherapy, and general clinical management strategies. The proposed diagnostic algorithm was applied to a series of 36 patients, four of whom met the criteria for preoperative biopsy. In three of these cases, early diagnosis of MPNSTs was achieved. Conclusions: Preoperative biopsy appears to be a safe and cost-effective tool for the early identification of MPNSTs. Early diagnosis may facilitate the use of neoadjuvant therapies-such as radiotherapy or chemotherapy-potentially enabling more radical surgical resection and improving overall patient outcomes.