Mental nerve neuropathy as initial symptom of cancer.

Numb chin syndrome is a rare cranial neuropathy. Knowledge of potential cancers that involve the mental nerve is mandatory, since it may lead in many cases to discovery of a neoplasia or to its recurrence. We describe a 55-year-old patient who complained for several days of numbness in the right side of his chin. No dental cause was found. What was found was an undiagnosed pulmonary carcinoma in metastasis. This possibility should be considered in the differential diagnosis.