Diagnostic Utility of Bronchial Brush-Tip Washings for the Immunohistochemical Assessment of Peripheral Lung Lesions

Abstract

Objectives: Immunohistochemistry (IHC) is an important component of lung cancer diagnosis and management, although performance can be limited due to tissue availability. We describe a novel technique for processing brush-tip washings (BTW) and evaluate the feasibility of IHC testing on these samples. Study Design: All patients who had cell blocks (CB) created from BTW following bronchoscopic investigation of peripheral lung lesions were included. CB were assessed for adequate material before undergoing IHC staining. Results: 75 patients were included in the study, with bronchoscopic diagnosis of malignancy achieved in 77%. Sixty-seven samples (89%) had sufficient cells for diagnosis on CB and 56 of these (84%) proved amenable to IHC. CB created from BTW were the sole specimens available for IHC subtyping in 7 patients (9%). Conclusions: CB are easily created from BTW and are a simple method for increasing the diagnostic utility of bronchoscopic specimens without increasing the risk or duration of bronchoscopy. IHC can be easily performed in a high proportion of cases, increasing the likelihood of accurate sub-typing of tumours following diagnostic bronchoscopy.

Molecular analysis of small tissue samples obtained via transbronchial lung biopsy using radial probe endobronchial ultrasound

“…Then, a radial probe EBUS (UM-S20-17S; Olympus) covered with a GS (K-201; Olympus) was advanced through a 2.0-mm-diameter working channel of the thin bronchoscope to target the peripheral lung lesion precisely. Once the lesion had been accurately identified, the radial probe EBUS was withdrawn, leaving the GS in place to allow brush cytology and forceps biopsy under fluoroscopic guidance [20–23]. Neither virtual bronchoscopy nor electromagnetic navigation was employed [14,15].…”

A Novel Approach to Detect Programed Death Ligand 1 (PD-L1) Status and Multiple Tumor Mutations Using a Single Non–Small-Cell Lung Cancer (NSCLC) Bronchoscopy Specimen

“…3 In addition to improving diagnosis and/or staging of lung cancer, small specimens collected by EBUS-guided procedures are being evaluated for their utility to identify molecular drivers of the disease. EBUS-transbronchial needle aspiration, 4 EBUSguided fine needle aspirates, 5 and bronchoscope cytology brush tip washings can provide adequate material for both immunohistochemical studies 6 and mutation sequencing of EGFR, KRAS, and BRAF genes. 7 Demand is increasing on molecular and sequencing technology to adapt with limited amounts of fixed tumor tissue, which are becoming the most commonly used samples for diagnostic and molecular pathology.…”

Sensitive molecular testing methods can demonstrate NSCLC driver mutations in malignant pleural effusion despite non-malignant cytology

“…Use of highly sensitive molecular techniques may also be of diagnostic utility in other lung cancer specimen types, such as bronchoscopic specimens (19). Such specimens may be non-diagnostic or not suitable for molecular testing (20,21), due to small specimen volume, or due to presence of a significant proportion of non-malignant cells (22). Molecular testing even on a single bronchial brushing specimen may significantly enhance diagnostic sensitivity of minimally invasive investigation (23,24), though this remains to be examined in future studies.…”