CYTOLOGIC CHARACTERISTICS OF MENINGEAL CARCINOMATOSIS - INCREASED DIAGNOSTIC-ACCURACY USING CARCINOEMBRYONIC ANTIGEN AND EPITHELIAL MEMBRANE ANTIGEN IMMUNOCYTOCHEMISTRY

Background and Objectives: Traditionally, the diagnosis of meningeal c arcinomatosis has been based on clinical suspicion and confirmed by cy tologic study of cerebrospinal fluid. However, routine cytologic study may fail to detect malignant cells in a relatively large number of ca ses. We used immunocytochemistry in an attempt to increase the sensiti vity of cytologic detection of malignant neoplasms in cerebrospinal fl uid. Materials and Methods: Thirty-eight consecutive cerebrospinal flu id specimens from patients with clinically suspected meningeal carcino matosis were selected for this study. Immunocytochemistry for carcinoe mbryonic antigen and epithelial membrane antigen were used on the arch ival Papanicolaou-stained cerebrospinal fluid preparations. Results: O f the 23 specimens from patients with proven meningeal carcinomatosis, 13 were correctly diagnosed using cytomorphologic criteria alone. The diagnosis of malignant neoplasm in 8 cytologically suspicious and 1 c ytologically negative specimen was confirmed using immunocytochemistry . All cases that were negative on follow-up were also negative cytolog ically and immunocytochemically. Conclusions: We conclude that in usin g common antibodies, such as carcinoembryonic antigen and epithelial m embrane antigen, the sensitivity of the cytologic diagnosis of meninge al carcinomatosis increases, and that previously Papanicolaou-stained preparations are suitable for immunocytochemical studies.