Mania resulting from brain stem tumor.

Mania usually represents one extreme of recurrent affective illness in patients with a genetic predisposition. Mania or hypomania is not generally known to signal the presence of an occult neoplasm; however, this possibility should be considered. The authors describe a 55-year-old man without personal or family history of affective disease whose manic behavior precipitated diagnosis of a metastatic mesencephalic tumor.