gms | German Medical Science

Introduction: Malignant peripheral nerve sheath tumor (MPNST) is a rare and very aggressive soft tissue tumor entitiy. Only 0.001% of all tumors are MPNST. However, patients harbouring neurofibromatosis type 1 (NF1) bear a 10% life-time risk to develop a MPNST. Treatment consists of radical surgery, radiation and chemotherapy. However, prognosis remains poor. Recently, new insights into molecular mechanism of tumor formation and growth became known leading to a new classification. We wanted to find out whether the predictive value of these markers was applicable to our patient group.

Material and methods:

Retrospectively 23 patients treated with MPNST in our hospital were analyzed. Clinical symptoms as pain, weakness, paresthesia and the presence of neurofibromatosis were recorded. In addition time from onset of symptoms to surgery, extent of resection and progression free period were assessed as well as recurrent tumors, metastases, further surgery, radiation and chemotherapy.Special attention was payed to the microscopic and histopatholgic findings and their possible correlation to the clinical course.

Results: Most patients (f 10/23, m 13/23) presented with pain in the affected area (21/23), 18 suffered from weakness and 20 from hypesthesia. 11/23 patients presented with NF1. In 22/23 surgery was performed initially. Afterwards, 10/23 received radiation, 1/23 radichemotherapy and 1/23 chemotherapy only. Until now, 4-years-survival rate is 43%. Expression of S100 was not associated with better survival rate. Patients with elevated Mib-1 and Ki-67 indices tended to have poorer prognosis as well as patients displaying vast tumor necrosis in the microscopic analysis.

Conclusion: In our series, outcome seemed to depend on association with NF1, presence of pain and extent of loss of function. Elevated MiB1 indices showed correlation with a higher aggressiveness. Further efforts are necessary to understand the value of tumor markers in MPNST to predict the individual clinical course.