关键词: 恶性外周神经鞘瘤, 　免疫组化, 　多学科协作诊疗

Abstract: Objective　To investigate the clinical and pathological features of malignant peripheral nerve sheath tumors (MPNST)，and increase the understanding of the diseases.　Methods　The clinical data of 22 cases of MPNST hospitalized in our hospital were collected. The pathological features and immunohistochemical phenotypes were observed by light microscopy and immunohistochemistry, and related literature review was carried out.　Results　Of the 22 MPNST patients, 10 were male and 12 female, whose age ranged between 15~82 years old, with a median age of 43 years. There were 3 cases located in the head and neck, 13 cases in trunk and proximal extremities, 5 cases in distal extremities, and 1 case with multiple locations over the body. The clinical manifestations were mainly local painless mass lumps. And the symptoms and signs were related to the location of the mass and the speed of progression. In the treatment, 19 patients underwent tumor resection, among which 6 were recommended for follow-up radiotherapy and 13 underwent chemotherapy (mainly with doxorubicin and ifosfamide). For immunohistochemistry, Vimentin (15/15), CD99 (8/8), IMP3 (10/11), S-100 protein (16/19) positive, and Ki-67 proliferation index ranged between 5%~80%. The 1-year case fatality rate was 45%, and the median survival time was 25 months. Local recurrence rate was 55% (12 cases), and distance metastasis rate was 32% (7 cases). Three cases got tumor free survival to date.　Conclusion　MPNSTs have special clinical and pathological characteristics. However, the clinical understanding of MPNST is insufficient. The study provides the key points of discrimination for this group of cases that can hopefully increase the diagnostic rate, and guide therapy and recovery.

Key words: Malignant peripheral nerve sheath tumors, 　Immunohistochemistry, 　Multiple disciplinary team (MDT)