Application of malignant pleural effusion cell blocks in the diagnosis and personalized treatment of advanced non-small cell lung carcinoma*

Abstract

Abstract Objective The aim of the study was to investigate the efficacy of immunocytochemistry and related gene detection using cell block for the diagnosis and individualized treatment of advanced lung cancer. Methods Sixty-five malignant pleural effusion specimens were collected to make cell blocks, which were used for hematoxylin and eosin (H&E) staining, immunocytochemical studies, and gene sequencing of the tumors to guide the individualized diagnoses and treatment of the given tumors. Results The tumor cells in the cell block sections were abundant in number with high quality cellular structures, and the histological morphological characteristics were partially maintained. Immunocytochemical staining was helpful in identifying the cell origin and tumor classification, and amplification refractory mutation system (ARMS) was used to determine the mutation status of epidermal growth factor receptor (EGFR). Of the 65 samples, 50 had a diagnosis of adenocarcinoma, 7 were pulmonary squamous cells, 6 were small cell carcinoma of the lung, and 2 were mesothelioma. The morphological features of the tumors were as follows: acinar formation, papillary and single cells for adenocarcinoma; intercellular bridges for squamous cell carcinoma; and morphology of the small cells is similar to that of the smear. Correlating with the results of immunocytochemical staining and clinical data analysis, 40 cases were confirmed as pulmonary adenocarcinoma, with an additional 4 cases of breast cancer, 3 cases of ovarian adenocarcinoma, and 3 cases of colorectal adenocarcinoma. Of the 47 non-small cell lung carcinoma (NSCLC) patients, EGFR mutations were detected in 26 cases (55.3%) by ARMS, with four mutation types: exon 19 deletion (13 cases, 50.0%), exon 2l point mutations L858R (11 cases, 42.3%) and L861Q (1 case, 3.8%), and exon 18 point mutation G719X (1 case, 3.8%). Conclusion Malignant pleural effusion cell blocks combined with immunocytochemical markers and molecular pathology are helpful for the diagnosis of advanced tumors, the identification of tumor properties and histological tumor origin, and the selection of individualized treatment for advanced lung cancer.