CARE FOR BENIGN TUMORS OF PERIPHERAL NERVES: RETROSPECTIVE REVIEW OF 25 YEARS EXPERIENCE

Abstract

Purpose of the study: Benign tumors of peripheral nerves are exceptional. Schwannomas predominate. Most tumors are revealed by tumefaction or pain over a nerve trajectory. The risk of degeneration is very low. Magnetic resonance imaging is the exploration of choice. The risk of sequelae or recurrence must nevertheless be determined with precision. We reviewed our experience with 93 benign tumors of peripheral nerves to search for factors predictive of prognosis.

Material and methods: This retrospective analysis included patients seen between 1979 and 2004. We collected a series of 89 patients, 41 women and 48 men, mean age 48 years, age range 18–80, with 93 benign tumors. Mean time from symptom onset (pain) to diagnosis was 20 months. The patients consulted for pain (n=78), presence of a mass (n=79) or both (n=66). Percussion produced paresthesia in 54 patients. Pre-operative magnetic resonance imaging was available for 45 patients. The same surgeon performed nerve microsurgery in all patients. A prior procedure had been performed in another institution for 23 patients. The tumors were: schwannoma (n=74), neurofibroma (n=14), plexiform neurofibroma (n=3), angiolipoma (n=1) and intranervous lipoma (n=1). Mean tumor size was 31 mm (range 7–120 mm). Tumors were located in the brachial plexus (n=13), the upper limb (n=29), the trunk (n=1) and the lower limb (n=50). Complete resection was achieved in 83 cases, with removal of a non-stimulatable fascicle in 50 cases and a motor fascicle in

4. Nerve repair was required for 11 cases: 5 by direct suture and 6 with grafts. Resection was impossible for 4 tumors treated by neurolysis, decompressive epineu-rotomy, biopsy and interfascicular dissection.

Results: Mean follow-up was 96 months (range 3–300). Outcome was very good for 42, good for 25, fair for 8 and poor for 5 (all seen secondarily). Nine patients were lost to follow-up. There were no cases of recurrence.

Discussion: Microsurgical procedures are necessary for resection of nerve tumors in order to preserve the fascicles and thus function. Unresectable tumors and secondary grafts yield les satisfactory results, in our series and in the literature. Similarly, the duration of the symptoms and the size of the tumor increase the risk of operative difficulty and sequelae. Despite high-performance imaging techniques, surgery is the only sure way to establish certain diagnosis.