ABSTRACT
Recently developed, endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive modality for mediastinal lymph node staging in lung cancer patients as well as for the diagnosis of mediastinal and hilar lymphadenopathy. It has been shown in systematic reviews and meta-analysis that a high diagnostic yield can be achieved with EBUS-TBNA for staging lung cancer. Though still not a standard of practice, this novel technology has attracted physicians and surgeons as an alternative modality to surgical biopsy for the assessment of the mediastinum. Standard cytology, thin layer preparations in liquid medium or cell blocks of cells obtained by EBUS-TBNA can be applicable not only for pathological diagnosis but also for further investigations such as immunohistochemistry and fluorescence in situ hybridization. In addition, samples obtained by EBUS-TBNA can also be used for molecular analysis. The key to a successful EBUS-TBNA is to understand the anatomy of the mediastinum as well as the basic steps of the procedure. Moreover, handling of the sample obtained by EBUS-TBNA is crucial for diagnosis since no amount of skill or interest of the interpreter can make up for a badly prepared sample. The goals of rapid on-site evaluation during EBUS-TBNA include determination of whether sampling of the target has been achieved and more importantly triage of samples to secondary investigations. This manuscript explains the detailed techniques of EBUS-TBNA to master this innovative procedure.
Subject(s)
Biopsy, Fine-Needle/methods , Bronchi/pathology , Bronchoscopy/methods , Endosonography/methods , Lymph Nodes/pathology , Ultrasonography, Interventional/methods , Anesthesia, Local , Bronchoscopes , Carcinoma, Non-Small-Cell Lung/pathology , Centrifugation , Conscious Sedation , Endosonography/instrumentation , Equipment Design , Granuloma/diagnosis , Granuloma/pathology , Humans , Lung Diseases/diagnosis , Lung Diseases/pathology , Lung Neoplasms/pathology , Lymphatic Metastasis/diagnosis , Lymphoma/diagnosis , Lymphoma/pathology , Mediastinum , Microtomy , Neoplasm Staging , Paraffin Embedding , Specimen Handling/methods , Staining and Labeling , Time Factors , Ultrasonography, Interventional/instrumentationABSTRACT
Although human malignant mesothelioma (HMM) is mainly caused by asbestos exposure, refractory ceramic fibres (RCFs) have been classified as possibly carcinogenic to humans on the basis of their biological effects in rodents' lung and pleura and in cultured cells. Hence, further investigations are needed to clarify the mechanism of fibre-induced carcinogenicity and to prevent use of harmful particles. In a previous study, mesotheliomas were found in hemizygous Nf2 (Nf2(+/-)) mice exposed to asbestos fibres, and showed similar alterations in genes at the Ink4 locus and in Trp53 as described in HMM. Here we found that Nf2(+/-) mice developed mesotheliomas after intra-peritoneal inoculation of a RCF sample (RCF1). Clinical features in exposed mice were similar to those observed in HMM, showing association between ascite and mesothelioma. Early passages of 12 mesothelioma cell cultures from ascites developed in RCF1-exposed Nf2(+/-) mice demonstrated frequent inactivation by deletion of genes at the Ink4 locus, and low rate of Trp53 point and insertion mutations. Nf2 gene was inactivated in all cultures. In most cases, co-inactivation of genes at the Ink4 locus and Nf2 was found and, at a lower rate, of Trp53 and Nf2. These results are the first to identify mutations in RCF-induced mesothelioma. They suggest that nf2 mutation is complementary of p15(Ink4b), p16(Ink4a) and p19(Arf) or p53 mutations and show similar profile of gene alterations resulting from exposure to ceramic or asbestos fibres in Nf2(+/-) mice, also consistent with the one found in HMM. These somatic genetic changes define different pathways of mesothelial cell transformation.