Mental nerve palsy in malignant lymphoma represents a clinical syndrome which has never been described previously. Eight cases are presented that have been observed and collected over a period of several years. Mental nerve palsy is a peripheral neuropathy: palpable masses or cervical lymphadenopathy were recorded as associated findings in 6 of the 8 cases and, in all probability, could be implicated as the etiology by producing direct pressure on either the inferior dental or mental nerve. Diffuse central nervous system involvement, when present, appeared to be coincidental rather than a causative factor, as reflected in the lack of response of the mental nerve to adequate brain stem irradiation, to which all other abnormally functioning cranial nerves responded. From the prognostic viewpoint, mental nerve palsy represents a hallmark of highly aggressive, rapidly progressive, and inexorably fatal malignant lymphoma. Radiation therapy is the treatment of choice. I t produces prompt regression of all associated lymph node masses and other soft-tissue infiltrations, and a demonstrable improvement in the mental nerve palsy. Treatment should be directed to the entire course of the inferior dental and mental nerves for the reasons discussed.
N ISOLATED CRANIAL NERVE PALSY ASSOCI-
A ated with a malignancy is, in general,