Guideline for the acquisition and preparation of conventional and endobronchial ultrasound-guided transbronchial needle aspiration specimens for the diagnosis and molecular testing of patients with known or suspected lung cancer.

RATIONALE: Conventional transbronchial needle aspiration (TBNA) and endobronchial ultrasound (EBUS)-TBNA are widely accepted tools for the diagnosis and staging of lung cancer and the initial procedure of choice for staging. Obtaining adequate specimens is key to provide a specific histologic and molecular diagnosis of lung cancer. OBJECTIVES: To develop practice guidelines on the acquisition and preparation of conventional TBNA and EBUS-TBNA specimens for the diagnosis and molecular testing of (suspected) lung cancer. We hope to improve the global unification of procedure standards, maximize the yield and identify areas for research. METHODS: Systematic electronic database searches were conducted to identify relevant studies for inclusion in the guideline [PubMed and the Cochrane Library (including the Cochrane Database of Systematic Reviews)]. MAIN RESULTS: The number of needle aspirations with both conventional TBNA and EBUS-TBNA was found to impact the diagnostic yield, with at least 3 passes needed for optimal performance. Neither needle gauge nor the use of miniforceps, the use of suction or the type of sedation/anesthesia has been found to improve the diagnostic yield for lung cancer. The use of rapid on-site cytology examination does not increase the diagnostic yield. Molecular analysis (i.e. EGFR, KRAS and ALK) can be routinely performed on the majority of cytological samples obtained by EBUS-TBNA and conventional TBNA. There does not appear to be a superior method for specimen preparation (i.e. slide staining, cell blocks or core tissue). It is likely that optimal specimen preparation may vary between institutions depending on the expertise of pathology colleagues.

Subtyping of nonsmall cell lung cancer on cytology specimens: reproducibility of cytopathologic diagnoses on sparse material.

Cytologic examination of fine-needle aspiration (material is increasingly used in diagnosing lung cancer. High interobserver agreement in distinguishing small-cell lung cancer from nonsmall-cell lung cancer (NSCLC) on cytologic material has been demonstrated. Because of new treatment-modalities, subclassification of NSCLC into squamous cell carcinoma (SQC) and non-SQC has clinical impact. Subclassification based on morphology alone may be difficult, but applying immunohistochemistry (IHC) to clot-material has proved helpful. When insufficient material is available to make a clot from the aspirate, cytoscrape (CS) can convert cytologic material into tissue fragments useful for IHC. The purpose of this study was to test the reproducibility of pulmonary malignant diagnoses, in particular distinction between subgroups of NSCLC, based on smeared material and IHC on CS. A consecutive series of May-Grunwald-Giemsa (MGG) stained smears and CS with IHC on material from 79 patients suspected of having lung cancer was included. The material was circulated twice to four pathologists. The diagnoses were categorized in five groups: SQC, adenocarcinoma of the lung, non-SQC, benign lesion and other forms of malignancy, including metastases. Reproducibility was analyzed using Kappa statistics. Interobserver reproducibility of the diagnoses in round 1 was good to very good (kappa 0.57-0.71) and very good in round 2 (0.63-0.80). Reproducibility of subclassification of NSCLC based on MGG stained smear and IHC on CS, was very good among experienced pathologists. With only sparse material available, CS should be used to achieve reproducible diagnoses, including subtyping of NSCLC.

Endoscopic ultrasound (EUS)-guided Trucut biopsy adds significant information to EUS-guided fine-needle aspiration in selected patients: a prospective study.

OBJECTIVE: Endoscopic ultrasound (EUS)-guided Trucut biopsy (EUS-TCB) has recently emerged as a method that seeks to overcome the limitations of EUS-guided fine needle aspiration (EUS-FNA) by providing a core-tissue specimen needed to increase the yield and accuracy of the diagnosis. The aim of our study was to evaluate whether EUS-TCB adds any information to EUS-FNA in selected patients and to assess the diagnostic yield, overall accuracy and complications of EUS-TCB as compared with EUS-FNA. MATERIAL AND METHODS: The study prospectively included 30 patients who had undergone both procedures. RESULTS: The yield of adequate tissue harvesting was similar for EUS-FNA and EUS-TCB (96.4% versus 89.3%, p=NS), with the same number of passes done. The diagnostic accuracy of EUS-FNA was also similar to that of EUS-TCB for the diagnosis of malignant mediastinal masses (73.7% versus 68.4%, p=NS). However, the accuracy for obtaining a specific diagnosis was significantly lower for EUS-FNA compared with EUS-TCB (5.3% and 68.4%, p<0.005). EUS-TCB did not appear to help as a rescue procedure in mediastinal tumours, after a false negative result of EUS-FNA. All cases of submucosal tumours were correctly classified by EUS-TCB as gastrointestinal stromal cell tumours (GISTs) or leiomyomas, while EUS-FNA raised only a suspicion of mesenchymal tumour. CONCLUSIONS: EUS-TCB was certainly useful when immunohistochemistry was needed, for example in submucosal tumours and lymphoma, as well as to confirm and characterize the primary or metastatic origin of mediastinal masses. The information provided by EUS-FNA and EUS-TCB is complementary, especially in selected cases where a complete histological diagnosis has an important impact on the clinical management.