The risk of peripheral nerve tumor biopsy in suspected benign etiologies
Shelby Burks, Roberto Perez-Roman, Allan Levi
Introduction: Peripheral nerve sheath tumors (PNST) are uncommon tumors with unique clinical and imaging features that present to a variety of medical practitioners, particularly surgeons. These lesions are often referred for percutaneous needle or open biopsy that can put functioning nerve +6 fascicles at risk and / or distort normal anatomical planes, making definitive resection more difficult.
Objective: Our goal was to evaluate the neurological risks of pre-operative biopsy in benign PNST.
Methods: Surgical cases collected retrospectively using a prospectively established database of benign PNST treated by a single surgeon.The neurologic status of patients before biopsy, before surgery, at 2-week follow-up, and at 3-month follow-up was assessed. Neurologic deficit was defined as new/worsening motor or sensory impairment or severe neuropathic pain.
Results: A total of 151 cases were included. Only 23.2% (35) of patients underwent pre-operative biopsy, but 42.9% of these experienced new or worsening neurologic exam immediately following biopsy. After definitive resection the rate of neurologic deficit was significantly different between the two groups with 60% of biopsy patients and 19% of those patients not biopsied experiencing decline in exam (F=25.72 p<0.001). Odds ratio for any post-operative deficit for biopsy was 6.40 (CI [2.8, 14.55], p<0.001). Univariate logistic regression of composite and individual neurologic deficit with patient age, sex, tumor type, and biopsy status showed that only biopsy was significantly associated with occurrence of any post-operative deficit and neuropathic pain.
Conclusions: Percutaneous or open biopsy should be avoided in nerve sheath tumors exhibiting benign features given the unacceptably high rate of neurologic risk.