A 10 year review of benign and malignant peripheral nerve sheath tumors in a single center: Clinical and radiographic features can help to differentiate benign from malignant lesions

Background: Malignant peripheral nerve sheath tumors are rare, and their aggressive nature mandates treatment in specialist centers. In contrast, benign peripheral nerve sheath tumors are common and are treated by a variety of specialist surgeons, including plastic surgeons. The authors aimed to detect features in the clinical presentation of peripheral nerve sheath tumors that point toward a diagnosis of malignant peripheral nerve sheath tumor and therefore prompt referral to a specialist center. Methods: All histologically diagnosed primary peripheral nerve sheath tumors from January of 1995 to December of 2004 were identified from histopathology records. Notes were reviewed and analyzed with regard to symptoms, signs, radiology, electrophysiology, surgery, and pathology. Statistical comparisons used Fisher's exact test and the Mann-Whitney test. Results: During the study period, 32 cases of malignant peripheral nerve sheath tumor in 30 patients were treated. Factors in the clinical evaluation that significantly predicted the presence of malignant peripheral nerve sheath tumor included site, large size, depth in relation to the deep fascia, short duration of symptoms, and pain. Magnetic resonance imaging and computed tomography were sensitive and specific ways of confirming the clinical diagnosis. Interestingly, schwannomata were harder to distinguish from malignant peripheral nerve sheath tumors both clinically and radiologically. Conclusions: The authors have reviewed their institutional experience of peripheral nerve sheath tumors over a 10-year period. Their results will help to focus clinical and radiologic investigation of patients presenting with these tumors.