Background: Peroneal neuropathies in patients with systemic cancer previously have been attributed to weight loss, but to the authors' knowledge other associated conditions have not been assessed, and the outcome of peroneal neuropathies in cancer patients has not been studied.
Methods: A retrospective chart review of patients evaluated at the Mayo Clinic between 1984 and 1993 with systemic malignant disease and a clinical diagnosis of peroneal neuropathy was performed to define factors associated with peroneal neuropathies and to assess outcome. All patients underwent neurologic examination and electromyography.
Results: Fifty-eight patients with systemic malignant disease were found to have a peroneal neuropathy. Peroneal neuropathies occurred more often in men (45 patients) than in women (13 patients). The median age of the patients was 70 years. The most common cancers were hematologic (12 patients) and pulmonary (11 patients), followed by tumors of the prostate (8 patients), gastrointestinal tract (7 patients), transitional cell (5 patients), breast (5 patients), and colon (5 patients), as well as sarcomas and melanoma (5 patients). The median time to the diagnosis of peroneal neuropathy after the diagnosis of cancer was 5 months. At the time of diagnosis, 34 patients had severe deficits, 19 had moderate deficits, and 5 had mild deficits. Associated factors included weight loss (occurring in 60% of patients), leg crossing (35% of patients), recent chemotherapy (16% of patients), cutaneous vasculitis (5% of patients), and local metastatic lesions (3% of patients). In nearly 50% of patients, peroneal neuropathy improved (25.9%) or resolved (22.4%). In 39.7% of patients, follow-up was inadequate because death occurred soon after diagnosis. Of the patients with adequate follow-up before death, 80% had either improvement (42.9%) or resolution (37.1%).
Conclusions: For those patients with systemic malignant disease in whom peroneal neuropathy develops, the outcome of the neuropathy is good, with the majority of patients achieving partial or complete resolution.