Diagnosis, Treatment and Survival of 65 Patients with Malignant Peripheral Nerve Sheath Tumors

Background: Malignant peripheral nerve sheath tumors (MPNST) account for up to 10% of all malignant soft tissue tumors in adults. Insufficient data are available on diagnosis, differential diagnosis and treatment modalities as well as prognosis.

Patients And Methods: Examining our sarcoma database from 1991 to 2004, we evaluated 65 patients with histologically-proven MPNST in terms of clinical, histopathological as well as prognostic factors.

Results: The median age was 54 years, the gender ratio was equal, the follow-up 36 months. Extremities were involved in 75% of cases, the trunk in 15% and the head in 9% respectively. A total of 9% of our patients presented with disease-positive lymph nodes, in 28%, distant metastases (primarily lung) occurred. A primary closure was performed in 60%; in 22%, a tendon transfer and flap coverage was necessary. In 11% of cases, the final treatment was amputation. The initial diagnoses which had to be revised during re-evaluation was 32.3%. The 5-year disease-free survival rate was 49%. Overall, 27% of patients first operated on at our Institution experienced local recurrence. The only significant negative prognostic factor for survival was occurrence of metastases.

Conclusion: Our data indicate, that MPNST are tumor entities with a high rate of initial diagnoses that subsequently need to be adjusted (32%). Therefore, reference pathology should be requested. Tumor localization close to major nerves often results in functional restrictions after tumor resection. Because of the low mean life expectancy, early functional reconstructions by tendon transfer should be performed instead of nerve repair. Despite less radical tumor excision with often marginal resections, the survival rate is comparable to that of the literature where patients were treated with more radical procedures.