Mental nerve neuropathy in systemic cancer. Report of three cases.

Mental nerve neuropathy (MNN), an uncommon neurologic symptom, was observed in three patients with cancer. In the first patient, MNN was the primary manifestation of an occult carcinoma of the lung. The second patient had bilateral MNN. In the third patient, MNN coexisted with symptomatic trigeminal neuralgia as a consequence of a cavum adenocarcinoma. A nontraumatic MNN must be considered a potentially ominous symptom that should prompt a search for cancer.