BACKGROUND: Prior studies have shown a high rate of local recurrence and a dismal overall prognosis in malignant peripheral nerve sheath tumors (MPNSTs). METHODS: Thirty-three patients who had undergone primary treatment for localized extremity MPNSTs between 1982 and 1992 were reviewed. These cases were derived from a prospective database of 890 adult extremity soft-tissue sarcomas (STS). MPNSTs were compared with other extremity STS. RESULTS: MPNSTs were more often high grade and deep compared with other extremity STS (94% vs. 72% [p = 0.009] and 97% vs. 76% [p = 0.01], respectively). Location (upper or lower extremity), size (> 5 cm vs. < or = 5 cm), and status of margins after surgical resection (positive or negative for disease) did not differ between the two groups. When deep and high-grade MPNSTs were compared with deep and high-grade STS, a more aggressive local treatment was applied to MPNSTs with a higher number of amputations for MPNSTs (32%) compared with STS (9%; p < 0.001). In order to obtain adequate margins, 16 of 21 MPNSTs arising from major nerves required either amputation (n = 8) or nerve resection (n = 8). Adjuvant radiotherapy was used in 48% of deep and high-grade MPNSTs, and 3-year local disease-free survival was 70%. Survival of deep and high-grade MPNSTs was comparable with other deep and high-grade STS (3-year survival 50% vs. 69%, respectively; p = 0.1). CONCLUSION: MPNSTs show adverse clinicopathologic features compared with other STS. However, when treated aggressively, MPNSTs have an outcome similar to other deep and high-grade extremity STS.
