Detection of ALK mRNA Transcripts in Liquid-based NSCLC ThinPrep Cytology Slides

Abstract

Introduction: Endobronchial ultrasound (EBUS)-guided sampling of the mediastinum has traditionally been performed by fine needle aspiration (FNA) for cytologic evaluation. The ProCore fine needle biopsy, used primarily to obtain intra-abdominal tissue core biopsies, has not been widely used for EBUS. The aim of this study was to evaluate our experience with EBUS-Procore of mediastinal nodes, and to compare its diagnostic utilization to that of conventional EBUS-FNA. Material and Methods: A retrospective review of all EBUS cases of mediastinal masses using a ProCore needle from December 2013 to March 2014 was performed. Patient demographics, anatomic site, number of procedure passes, on-site immediate evaluation, final pathology reports, and ancillary test results were recorded. All specimen slides and cell blocks were evaluated scoring lesion and contamination cellularity (0 Z acellular, 1 Z scant, 2 Z moderate, and 3 Z abundant). Results: There were 18 EBUS cases of mediastinal lymph nodes using Procore in patients (12 female, 6 male) of average age 57 years (range, 3380 years). FNA was followed by Procore biopsy in all cases, except one where only Procore was performed. Cases included benign (granulomas), atypical, and malignant (carcinoma) diagnoses. More FNAs were satisfactory (with 2 unsatisfactory cases) than Procores (with 7 unsatisfactory cases). The 2 non-diagnostic FNA cases remained unsatisfactory with subsequent Procore. More passes were performed with FNA (4/case) than Procore (2.6/case). On average, FNA provided greater cellularity of lesional material (smear score Z 2; cell block score Z 1.4) than Procore (smear score Z 1.4; cell block score Z 1.4). However, FNAs contained more bronchial contamination (smear score Z 1.6; cell block score Z 1) than Procore (smear score Z 1; cell block score Z 0.4). Both sample types contained similar bronchial and blood contamination. Ancillary studies (special stains, immunostains, FISH, molecular) were equally successful using cell blocks from both specimen types. Conclusions: Our preliminary experience shows that EBUS-guided Procore sampling of mediastinal lymph nodes is feasible. Although FNA samples appear to provide more diagnostic cellular material in this pilot series, fewer subsequent Procore passes were required to achieve satisfactory specimens. Procore specimens also contained less obscuring bronchial contamination. Evaluation of more cases and more experience with this new technique is necessary to determine if the diagnostic yield using Procore during EBUS can be improved.