Nevertheless, the cytological diagnosis of pulmonary
nodules sampled by fine-needle aspiration cytology (FNAC) presented three main problems for the pathologist: a) the small amount of cellular specimens, b) the correct characterization of tumor histotype, and c) the report of biological information predictive of targeted therapy response. Conventional cytology can often provide insufficient material to answer these problems, while the availability of cell blocks allowed to perform multiple analyses as IHC, CISH/FISH and eventually gene mutations . In a retrospective series of 33 pulmonary tumors, we investigated the feasibility and reliability of CISH performed in cell blocks obtained from FNAC, to detect EGFR gene copy number both in primary NSCLC and mCRC lung nodules. In addition, we compared CISH
to FISH and IHC results. Materials and methods Patients and samples selleck kinase inhibitor Cell blocks from paraffin embedded FNAC of 33 lung neoplastic nodules were retrospectively selected from the Pathology Department Archives of the National Cancer Institute of Bari, Italy. Twenty primary lung carcinomas, 18 from male and 2 from female patients, and 13 metastatic lung nodules from CRC (10 males and 3 females) were included in this study. Five of the 20 NSCLC were squamous cell carcinomas (SCC), 8 large cell carcinomas (LCC), and 7 adenocarcinomas (ADC). The median age of patients was 67 (range: 31-84 years). FNAC samples were obtained with a CIBA 22-gauge needle (length 15 cm), and the aspiration procedure was performed under computed Ceritinib mw tomography (CT) guidance. All patients provided their written consent for use of the samples for research purposes. Cell Fenbendazole Block Procedure Cell blocks were prepared spinning the FNAC cellular specimens, fixed in 10% buffered formalin, at 1000 revolutions per minute for 10 minutes.
After centrifugation, the sediment was re-suspended in 95° ethyl alcohol for 10 minutes and submitted to a second centrifugation. Then, the packed sediment was removed with a spatula and wrapped in lens paper. The wrapped sediment was embedded in paraffin according to conventional histological techniques after a short processing cycle with xylene. Five consecutive 3-4 μm thick sections were cut from cell block of all 33 cases and processed by IHC to evaluate EGFR expression and by CISH and FISH to analyze gene amplification. The cytological slides were reviewed by a pathologist (GS), who verified the diagnosis and the percentage of neoplastic cells. Immunohistochemistry The immunohistochemical assay for EGFR expression was performed on tissue sections from cell blocks using the EGFR PharmDx kit (Dako, Milan, Italy). The deparaffinized and rehydrated sections were pre-treated in an enzyme solution (Proteinase-k) at room temperature (RT) for 5 minutes.