ATOMIC-FORCE MICROSCOPY IN EFFUSION CYTOLOGY

OBJECTIVE: To investigate whether atomic force microscopy (AFM) in com bination with classical light microscopy allows simple identification of surface structures of cells from pleural and ascitic fluids for dia gnostic purposes in place of scanning electron microscopy (SEM). STUDY DESIGN: We examined a total of 180 cells obtained from 9 reactive ple ural or peritoneal effusions, 14 associated with carcinomatosis from h istologically confirmed tumors and 5 from mesotheliomas. Cells of inte rest were selected in air-dried, uncovered, May Grunwald-Giemsa (MGG)- stained smears and subsequently investigated by AFM. Incorporation of a very compact AFM scanner into the nose piece of a conventional Axios cope light microscope allowed alternating application of both techniqu es. RESULTS: AFM was able to detect cell surface structures, such as m icrovilli, phagocytic pits, secretory blebs and lytic holes. The image resolution was sufficient but not its good as that with SEM. We found differences in number, length and diameter of microvilli between cell s from mesotheliomas and from metastatic adenocarcinomas. CONCLUSION: As AFM can be carried out in combination with light microscopy quickly and easily on uncovered, MGG-stained smears, we propose this method a s a suitable tool for obtaining additional useful information in routi ne cytologic diagnosis of effusions.