Lip paresthesia associated with a jaw mass. A case is reported in which mandibular swelling and lower lip numbness were the first signs of a metastatic adenocarcinoma of the lung. The development of paresthesia, with or without other oral symptoms, requires that a diagnosis of malignancy be considered until confirmed or ruled out by tissue biopsy. A thorough head and neck examination in all patients, especially in those whose history or habits may indicate increased risk of malignancy is necessary. 