Numb chin syndrome in acute myeloid leukemia.

Numb chin syndrome (NCS) is a rare cranial neuropathy characterized by facial numbness in the distribution of the mental branch of the inferior alveolar nerve. Although commonly associated with local trauma, NCS can indicate an underlying neoplastic condition. Although NCS is most commonly associated with nonmalignant disease states, it may be the presenting symptom of a systemic malignancy, and its prompt recognition is essential for proper management. NCS is associated with a variety of neoplastic conditions but is most commonly seen with lymphoproliferative conditions, breast cancer and prostate cancer. When confronted with a possible diagnosis of NCS, clinical evaluation should include evaluation for occult malignancy or relapse of any known previous cancer. In this study, a case of a patient with NCS in the context of a new diagnosis of acute myeloid leukemia with differentiation with a t(8;21) translocation is presented and the literature regarding the multiple etiologies and significance of NCS reviewed.