Carcinomatous meningitis as the initial manifestation of breast cancer.

Report is made of an elderly woman in whom carcinomatous meningitis was the initial manifestation of breast cancer. The patient presented with nonfocal neurologic symptoms. Cytologic examination of cerebrospinal fluid (CSF) revealed malignant cells arranged either in loose clusters or as isolated single cells. The morphology of the cells, some of which had a signet-ring configuration with a crescent-shaped nucleus as well as prominent round nucleoli, suggested a breast primary, which was proven by subsequent histologic study.