Rapid On‐site Molecular Evaluation in thyroid cytopathology: A same‐day cytological and molecular diagnosis

Abstract

Background Thyroid fine‐needle aspirates (FNAs) with undetermined morphology can be outsourced to centralized laboratories for comprehensive molecular profiling. When a local, rapid screening rules out easily detectable BRAF and NRAS mutations outsourcing is minimized, leading to cost savings. The fully automated Idylla technology, that does not require trained staff, is an emerging option. However, Idylla platform has only been validated to process formalin fixed paraffin embedded (FFPE) sections. Here we investigate whether also the FNA needle rinse could be genotyped by the same cytopathologist who performs the FNA, a procedure that can be termed rapid on site molecular evaluation (ROME). Methods To validate this approach, the Idylla BRAF and NRAS Test was performed on the rinses from 25 simulated (bench‐top) FNAs, in a first part of the study. Genotyping data were compared with those obtained on matched histological FFPE blocks. The second part of the study was carried out on 25 prospectively collected routine FNAs to assess the performance of the Idylla BRAF and NRAS assay against a gold standard real time polymerase chain reaction method. Results Idylla NRAS‐BRAF Mutation Test was performed on needle rinse as well as histological FFPE blocks. A sensitivity of 88.9%, a specificity of 100.0% were obtained comparing the Idylla NRAS‐BRAF Mutation Test on needle rinse to the reference method. Conclusions The FNA needle rinse can be directly genotyped. This obviates the need of cell block preparation, making possible a rapid combined morphological and molecular evaluation. Since DNA extraction is no longer necessary, the cytopathologist can perform ROME him/herself.

Testing EGFR with Idylla on Cytological Specimens of Lung Cancer: A Review

“…It is well known that it is best for the collection of the sample to be performed directly by the cytopathologist who will then evaluate it microscopically, and not by some other professional figure [ 85 ]. In the procedure known as rapid on-site evaluation (ROSE), the cytopathologist can smear the material on glass slides, air-dry them, stain them with a quick cytological stain (such as Diff-Quik) and evaluate them for adequacy on the spot, using a microscope [ 86 , 87 , 88 , 89 ].…”

“…For comparison, in one of the studies included in this review, the average turn-around time was 2 days with Idylla versus 14–28 days with NGS [ 7 ]. If the freshly aspirated material is centrifuged and pipetted directly in the cartridge, the results can be ready in less than three hours from the biopsy [ 85 ]. Such speed is unparalleled by NGS and even by other PCR-based methods.…”

“…As De Luca and colleagues have shown, the cartridge can even be loaded directly by the cytopathologist with minimal training [ 85 ]. If the Idylla workstation is placed in the same room, or if the cartridge is run right away, then this means that the test results will be ready in a few hours from the sampling.…”

Predictive molecular pathology in the time of COVID-19

“…In our experience, the possibility for a highly trained molecular pathologist to visually inspect the RT-PCR curves online, thanks the web-based Idylla Explore application, is crucial. 19 In fact, although most cases (95%) were diagnosed by the fully automated approach only, on some occasions, NGS was still carried out to refine uncertain results displaying RT-PCR curves of undetermined interpretation. 20 Moreover, not all clinically relevant biomarkers are testable by Idylla; as an example, automated assays for KIT and PDGFRA gene evaluations have not been developed yet.…”

Predictive molecular pathology in the time of coronavirus disease (COVID-19) in Europe

“…Highly trained molecular pathologists are crucial to visually inspect the RT-PCR curves of undetermined interpretation and to select cases requiring a second confirmatory technique. 26 27 …”