Detection of rare malignant cells and their apoptotic fragments in cerebrospinal fluid.

Routine cerebrospinal fluid cytology often fails to detect small numbers of malignant cells exfoliated from primary lymphomas of the central nervous system and metastatic carcinomas. Immunocytochemistry on poly-L-lysine-coated slides was optimised to permit unequivocal identification of a single carcinoma cell in 1 mL of cerebrospinal fluid, as well as carcinoma cell-derived apoptotic bodies that themselves contribute to enhanced diagnostic sensitivity.