Immunocytochemistry of cytological specimens as a diagnostic and prognostic tool.

In the last two decades, immunocytochemistry has been increasingly used in diagnostic cytopathology and is now part of the routine work in a cytopathological laboratory. Immunostaining successfully complements morphological studies for the identification and classification of tumours, when performed with well-defined monoclonal antibodies (MoAbs). This article will briefly review the MoAbs most frequently utilized for diagnostic purposes and the field in which they may be applied. MoAbs against biological markers for malignant transformation and tumour progression, are now available and the feasibility of their application to clinical cytopathology will be discussed.