Chin numbness: a symptom that should not be underestimated: a review of 12 cases.

The numb chin syndrome (NCS) is characterized by facial numbness along the distribution of the mental branch of the trigeminal nerve. Most cases of this syndrome that are not dental in origin have been associated with malignant tumors or diffuse metastatic disease, particularly with underlying lymphoproliferative diseases and breast cancer. NCS can appear together with other signs of neoplastic dissemination or constitute the presenting symptom of the disease. The appearance of this mental nerve neuropathy should be considered as a significant symptom for clinicians, and investigations to detect a possible cancer should be mandatory. We report 12 patients with the NCS as the presenting and isolated symptom of a generalized malignancy.