Immunocytochemical analysis of cytocentrifuged fine needle aspirates. A study based on lung tumors aspirated in vitro.

The value of Cytospin preparations of fine needle aspiration (FNA) biopsy material for immunocytochemical analysis was investigated using aspirates obtained from 23 resected human lung tumors. The results were compared with those on cryostat sections from the same tumors. The Cytospin preparations of the FNA biopsies gave the best immunostaining reactions and enabled a comprehensive range of monoclonal antibodies (MAbs) to be utilized. The quality of the Cytospin immunostaining compared favorably with that on cryostat sections of the same tumors and generally yielded a similar immunophenotype. However, the Cytospin preparations were not suitable for staining with MAb Ki67, which detects an antigen associated with cellular proliferation. With Ki67, conventionally prepared smears were much superior and enabled an assessment of tumor growth fraction that concurred with the growth fraction calculated from cryostat sections in most cases.