Mental neuropathy from systemic cancer.

Nineteen patients with mental neuropathy secondary to systemic cancer are described. In nine patients, the numb chin was the presenting symptom of a neoplasm. Nine patients had lymphoreticular malignancies, and the others had a variety of solid tumors. Radiograms of the mandible were abnormal in 5 of 12 patients. The cerebrospinal fluid contained malignant cells in two. Resolution, complete or partial, occurred in 16 of 19 patients receiving radiation or chemotherapy, including 8 who received chemotherapy alone. Sixteen of the 19 patients died within 17 months of the onset of the neuropathy. A nontraumatic mental neuropathy should initiate a search for cancer.