Correction: Modelling outcomes after paediatric brain injury with admission laboratory values: a machine-learning approach.

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Modelling outcomes after paediatric brain injury with admission laboratory values: a machine-learning approach.

BACKGROUND: Severe traumatic brain injury (TBI) is a leading cause of mortality in children, but the accurate prediction of outcomes at the point of admission remains very challenging. Admission laboratory results are a promising potential source of prognostic data, but have not been widely explored in paediatric cohorts. Herein, we use machine-learning methods to analyse 14 different serum parameters together and develop a prognostic model to predict 6-month outcomes in children with severe TBI. METHODS: A retrospective review of patients admitted to Cambridge University Hospital's Paediatric Intensive Care Unit between 2009 and 2013 with a TBI. The data for 14 admission serum parameters were recorded. Logistic regression and a support vector machine (SVM) were trained with these data against dichotimised outcomes from the recorded 6-month Glasgow Outcome Scale. RESULTS: Ninety-four patients were identified. Admission levels of lactate, H+, and glucose were identified as being the most informative of 6-month outcomes. Four different models were produced. The SVM using just the three most informative parameters was the best able to predict favourable outcomes at 6 months (sensitivity = 80%, specificity = 99%). CONCLUSIONS: Our results demonstrate the potential for highly accurate outcome prediction after severe paediatric TBI using admission laboratory data.

Pre-hospital Predictors of Impaired ICP Trends in Continuous Monitoring of Paediatric Traumatic Brain Injury Patients.

OBJECTIVE: Although secondary insults such as raised intracranial pressure (ICP) or cardiovascular compromise strongly contribute to morbidity, a growing interest can be noticed in how the pre-hospital management can affect outcomes after traumatic brain injury (TBI). The objective of this study was to determine whether pre-hospital co-morbidity has influence on patterns of continuously measured waveforms of intracranial physiology after paediatric TBI. MATERIALS AND METHODS: Thirty-nine patients (mean age, 10 years; range, 0.5-15) admitted between 2002 and 2015 were used for the current analysis. Pre-hospital motor score, pupil reactivity, pre-hospital hypoxia (SpO2 < 90%) and hypotension (mean arterial pressure < 70 mmHg) were documented. ICP and arterial blood pressure (ABP) were monitored continuously with an intraparenchymal microtransducer and an indwelling arterial line. Pressure monitors were connected to bedside computers running ICM+ software. Pressure reactivity was determined as the moving correlation between 30 10-s averages of ABP and ICP (PRx). The mean ICP and PRx were calculated for the whole monitoring period for each patient. RESULTS: Those with pre-hospital hypotension were susceptible to higher ICP [20 (IQR 8) vs 13 (IQR 6) mmHg; p = 0.01] and more frequent ICP plateau waves [median = 0 (IQR 1), median = 4 (IQR 9); p = 0.001], despite having similar MAP, CPP and PRx during monitoring. Those with unreactive pupils tended to have higher ICP than those with reactive pupils (18 vs 14 mmHg, p = 0.08). Pre-hospital hypoxia, motor score and pupillary reactivity were not related to subsequent monitored intracranial or systemic physiology. CONCLUSION: In paediatric TBI, pre-hospital hypotension is associated with increased ICP in the intensive care unit.

Computed Tomography Indicators of Deranged Intracranial Physiology in Paediatric Traumatic Brain Injury.

OBJECTIVE: Computed tomography (CT) of the brain can allow rapid assessment of intracranial pathology after traumatic brain injury (TBI). Frequently in paediatric TBI, CT imaging can fail to display the classical features of severe brain injury with raised intracranial pressure. The objective of this study was to determine early CT brain features that influence intracranial or systemic physiological trends following paediatric TBI. MATERIALS AND METHODS: Thirty-three patients (mean age, 10 years; range, 0.5-16) admitted between 2002 and 2015 were used for the current analysis. Presence of petechial haemorrhages, basal cistern compression, subarachnoid blood, midline shift and extra-axial masses on the initial trauma CT head were assessed. ICP and arterial blood pressure (ABP) were then monitored continuously with an intraparenchymal microtransducer and an indwelling arterial line. Pressure monitors were connected to bedside computers running ICM+ software. Pressure reactivity was determined as the moving correlation between 30, 10-s averages of ABP and ICP (PRx). The mean ICP, ABP, cerebral perfusion pressure (CPP; ABP minus ICP) and PRx were calculated for the whole monitoring period for each patient. RESULTS: The presence of subarachnoid blood was related to higher ICP, higher ABP and a trend toward higher PRx. Smaller basal cisterns were related to increased ICP (R = -0.42, p = 0.02), impaired PRx (R = -0.5, p = 0.003). The presence of an extra-axial mass was associated with deranged PRx (-0.02 vs. 0.41, p = 0.003) and a trend toward higher ICP (14 vs. 40, p = 0.07). Interestingly the degree of midline shift was not related to ICP or PRx. CONCLUSIONS: The size of the basal cisterns, the presence of subarachnoid blood or an extra-axial mass are all related to disturbed ICP and pressure reactivity in this paediatric TBI cohort. Patients with these features are ideal candidates for invasive multimodal monitoring.

Correlating optic nerve sheath diameter with opening intracranial pressure in pediatric traumatic brain injury.

INTRODUCTION: The use of clinical markers to predict intracranial pressure (ICP) is desirable as a first-line measure to assist in decision making as to whether invasive monitoring is required. Correlations between ICP and optic nerve sheath diameter (ONSD) using CT and MRI have been observed in adult populations. However, data on this modality in children is less well documented. METHODS: ONSD was measured by independent observers and correlated with opening ICP at insertion of invasive monitoring probes in pediatric traumatic brain injury patients admitted to Addenbrookes Hospital between January 2009 and December 2013. RESULTS: Thirty-six patients with a mean age of 8.2 y were admitted to the Pediatric Intensive Care Unit (PICU) with a traumatic head injury and required invasive neurosurgical monitoring. The median ICP was 18 ± 10 mmHg (median ± IQR), the median right ONSD was 5.6 ± 2.5 mm and the left was 5.9 ± 3.2 mm. The Intraclass correlation between observers was 0.91 (P < 0.0001). The correlation of mean ONSD and max ONSD with ICP was 0.712 (P < 0.0001) and 0.713 (P < 0.0001), respectively. Area under ROC curve for both mean and max ONSD is 0.85 (95% CI: 0.73-0.98). CONCLUSION: Where pediatric patients present with an ONSD of over 6.1 mm following a traumatic brain injury (TBI), ICP monitoring should be implemented.

Imatinib Treatment of Lymphangiomatosis (Generalized Lymphatic Anomaly).

Lymphangiomatosis (eg, generalized lymphatic anomaly) is an abnormal proliferation of lymphatic endothelial cells. It is often a childhood disease, but it may present in adulthood by infiltrating organs and cause obstruction, bleeding, or disruption of lymphatic flow. Pulmonary involvement may be mild or cause diffuse interstitial lung disease, airway obstruction, hemoptysis, chylothorax, chylopericardium, and culminate in respiratory failure. Treatment has been limited to surgical resection or drainage procedures because there is no accepted effective systemic therapy. This report presents a patient with lymphangiomatosis and life-threatening hemoptysis in whom positive immunostaining forc-KITsuggested upregulation of tyrosine kinase and whose disease was controlled with imatinib.

Molecular heterogeneity of head and neck squamous cell carcinoma defined by next-generation sequencing.

Head and neck squamous cell carcinoma (HNSCC) can be divided into two different clinical entities based on their association with high-risk subtypes of human papilloma virus (HPV16 and HPV18). Dissimilarities in prognosis and molecular profiles have attracted much attention in recent years, in part because of increasing rates of HPV infection in HNSCC; however, the underlying mechanisms and detailed genetic profiles that set these tumors apart are still elusive. To elucidate oncogenic pathways in HNSCC with and without HPV infection, we used targeted next-generation sequencing to interrogate single-nucleotide polymorphisms (SNPs) in 50 cancer-related genes. We detected SNPs in 25 of these genes from HNSCC tissue specimens with and without HPV infection. In 5 of the 25 genes, variant patterns were similar regardless of HPV infection status. A greater number of sequence variants in genes from the tyrosine kinase receptors and their associated pathways were preferentially present in HPV(+) specimens. SNPs in genes related to tumor-suppressor functions were more prevalent in HPV(-) HNSCC specimens. The observations may help to elucidate mechanisms involved in the molecular pathogenesis of two clinically diverse subclasses of HNSCC. Over-representation of SNPs in either HPV(+) or HPV(-) HNSCC is another indicator of potentially actionable sequence variants for targeted therapy.

Diffuse cerebral vasospasm following resection of a hypoglossal schwannoma in a child.

Diffuse cerebral vasospasm is a rare complication following tumour resection. This phenomenon seems to be even rarer in the paediatric population and more so following resections of posterior fossa tumours. Here we report diffuse cerebral vasospasm in a child with hypoglossal nerve Schwannoma eight days following resection of the tumour.

Entamoeba histolytica: gene expression analysis of cells invading tissues.

Entamoeba histolytica is a protozoan parasite that presents a risk to the health of millions of people worldwide. Due to the existence of different clinical forms caused by the parasite and also different virulence levels presented by one strain, one would expect differences in the profile of gene transcripts between virulent and nonvirulent cultures. In this study we used the differential display to select gene segments related to invasiveness of amoeba. One Brazilian strain of E. histolytica in two conditions, able or not to cause lesions in experimental animals, was used. RNA from this strain, was used to study the differential expression of genes. 29 specific gene fragments differentially expressed in the virulent strain were selected. By real-time PCR, six of these genes had confirmed their differential expression in the virulent culture. These genes may have important roles in triggering invasive amoebiasis and may be related to adaptation of trophozoites to difficulties encountered during colonization of the intestinal epithelium and liver tissue. Future studies with these genes may elucidate its actual role in tissue invasion by E. histolytica generating new pathways for diagnosis and treatment of amoebiasis.

Clinical Utility and Reimbursement of Next-Generation Sequencing-Based Testing for Myeloid Malignancies.

Next-generation sequencing is becoming increasingly important for the diagnosis, risk stratification, and management of patients with established or suspected myeloid malignancies. These tests are being incorporated into clinical practice guidelines and many genetic alterations now constitute disease classification criteria. However, the reimbursement for these tests is uncertain. This study analyzed the clinical impact, ordering practices, prior authorization, and reimbursement outcomes of 505 samples from 477 patients sequenced with a 50-gene myeloid next-generation sequencing panel or a 15-gene myeloproliferative neoplasm subpanel. Overall, 98% (496 of 505) of tests provided clinically useful data. Eighty-nine percent of test results, including negative findings, informed or clarified potential diagnoses, 94% of results informed potential prognoses, and 19% of tests identified a potential therapeutic target. Sequencing results helped risk-stratify patients whose bone marrow biopsy specimens were inconclusive for dysplasia, monitor genetic evolution associated with disease progression, and delineate patients with mutation-defined diagnoses. Despite the clinical value, prior authorization from commercial payors or managed government payors was approved for less than half (45%) of requests. Only 51% of all cases were reimbursed, with lack of medical necessity frequently cited as a reason for denial. This study demonstrates the existence of a substantial gap between clinical utility and payor policies on test reimbursement.

Combined intracranial pressure monitoring and cerebrospinal fluid infusion study to guide management of slit ventricle syndrome.

INTRODUCTION: Slit ventricle syndrome remains a complex entity presenting a considerable challenge to treat successfully. This study aims to demonstrate the application of dual intracranial pressure (ICP) and infusion studies together with the novel shunt occlusion test in both a diagnostic and therapeutic role. CASE REPORT: An 8-year-old child had aqueduct stenosis treated with a ventriculoperitoneal shunt (medium-pressure valve). The presentation was of headaches with papilloedema. Imaging with both computed tomography and magnetic resonance imaging revealed slit ventricles. Initially a shunt exploration revealed distal obstruction that was treated together with insertion of a paediatric strata II regular valve; however, the child continued to deteriorate. Overnight ICP monitoring revealed dramatically raised ICP with poor compensatory reserve. Intra-operative infusion study revealed a shunt that was patent distally but with proximal obstruction. A subtemporal decompression ipsilateral to the shunt was performed together with adjustment of the paediatric strata II regular valve to 2.5 in order to prevent overdrainage. This led to normalisation of ICP, resolution of papilloedema and symptomatic improvement. DISCUSSION: We demonstrate how combined ICP monitoring and shunt infusion studies can be used to help guide management. Unilateral subtemporal decompressions and preventing shunt overdrainage can result in normalisation of ICP and cerebrospinal fluid dynamics.

Quality metrics for enhanced performance of an NGS panel using single-vial amplification technology.

AIMS: Targeted next-generation sequencing (NGS) panels, which identify genomic alterations, are the stronghold of molecular oncology laboratories. In spite of technological advances, the quantity and quality of DNA from formalin-fixed paraffin-embedded tissue and paucicellular specimens are barriers to successful sequencing. Here, we describe an NGS assay employing single tube stem-loop inhibition mediated amplification technology that delivers highly accurate results with low input DNA. Rigorous quality metrics, regular monitoring and in-depth validation make the test attractive for clinical laboratories. METHODS: The study used a customised NGS panel, targeting 48 genes across several solid tumour types. Validation, in accordance with guidelines from New York State, sequenced patient samples harbouring 136 known variants, including single-nucleotide variants (SNVs) and indels. Specimen types included formalin-fixed paraffin embedded blocks, core biopsies and cytology material. Neoplastic cellularity of the tumours ranged from 10% to 80%. RESULTS: The assay was highly specific and sensitive with excellent accuracy, reproducibility and repeatability/precision. Concordant results for identification of SNVs and indels were obtained from specimens with DNA input of 2-3 ng, tissue with 10% neoplastic cellularity and variant allelic frequencies of 2.5%-3%. Over 99% of the target areas are shown to achieve at least 500X coverage when parsed through two bioinformatics pipelines. With over 2000 clinical specimens analysed, the success of the panel for reporting of results is 95.3% CONCLUSIONS: The advanced technology enables accurate identification of clinically relevant variants with uniformity of coverage and an impressive turn-around-time. The overall workflow and cost-effectiveness provide added value.

Benchmarking bioinformatics approaches for tumour mutational burden evaluation from a large cancer panel against whole-exome sequencing.

Tumour mutational burden (TMB) is used to predict response to immunotherapies. Although several groups have proposed calculation methods for TMB, a clear consensus has not yet emerged. In this study, we explored TMB calculation approaches with a 586-gene cancer panel (1.75 Mb) benchmarked to TMB measured by whole-exome sequencing (WES), using 30 samples across a range of tumour types. We explored variant allelic fraction (VAF) cut-offs of 5% and 10%, population database filtering at 0.001, 0.0001 and 0.000025, as well as different combinations of synonymous, insertion/deletion and intronic (splice site) variants, as well as exclusion of hotspot mutations, and examined the effect on TMB correlation. Good correlation (Spearman, range 0.66-0.78) between WES and panel TMB was seen across all methods evaluated. Each method of TMB calculation evaluated showed good positive per cent agreement and negative per cent agreement using 10 mutations/Mb as a cut-off, suggesting that multiple TMB calculation approaches may yield comparable results.

RNA Sequencing for Solid Tumor Fusion Gene Detection: Proficiency Testing Practice and Performance Comparison.

CONTEXT.­: Next-generation sequencing-based approaches using RNA have increasingly been used by clinical laboratories for the detection of fusion genes, intragenic rearrangements, and exon-skipping events. Correspondingly, the College of American Pathologists (CAP) has advanced RNA sequencing proficiency testing (PT) to ensure optimal performance of these assays. OBJECTIVE.­: To report on laboratory performance and practices of RNA sequencing for the detection of fusion genes, intragenic rearrangements, and exon-skipping events using CAP PT data from 8 mailings (2018-A through 2021-B). DESIGN.­: CAP PT RNA sequencing program results from 153 laboratories across 24 proficiency test specimens, interrogating 22 distinct engineered fusion transcripts, were analyzed for correct identification of the fusion event, associated performance variables, and laboratory practices. RESULTS.­: Overall, the 4-year program detection rate (sensitivity) was 95.5% (1486 of 1556 results). False-negative rates were 3.6% (53 of 1463) and 18.3% (17 of 93) for fusion gene and intragenic rearrangement/exon-skipping events, respectively. Only 19 false-positive results were reported among the 8 PT mailings, and most were likely the result of preanalytical or postanalytical errors. There were no practice characteristics (eg, instrumentation, sequencing method) significantly associated with the fusion detection results. CONCLUSIONS.­: These data reveal a high overall sensitivity and specificity for fusion gene detection by participating laboratories using clinical RNA sequencing. Performance was comparable across all laboratories, regardless of methodology. The fraction of false-negative results for intragenic rearrangement/exon-skipping events was greater than that for the chimeric fusion genes. False-negative results could not be attributed to any specific practice characteristics.

Pan-tumor screening for NTRK gene fusions using pan-TRK immunohistochemistry and RNA NGS fusion panel testing.

Targetable NTRK gene fusions can be detected across tumor types using methodologies such as pan-TRK IHC, DNA or RNA NGS testing, or FISH. Challenges for implementation of clinical testing for NTRK fusions may arise due to the range in NTRK fusion prevalence across tumors, endogenous levels of TRK expression in tissues, and the large number of potential fusion partners. In this study, we examined our experience evaluating driver mutation negative lung, urothelial or cholangiocarcinoma cases, in addition to cases with positive, equivocal, or weak staining by pan-TRK IHC for NTRK fusions. 63/127 (49.6%) of these cases were positive for pan-TRK IHC, of which 71.4% showed weak or focal staining, potentially due to physiologic or non-specific TRK expression. Of these 127 cases, 4 harbored a NTRK fusion (1 fusion was seen in two separate samples from the same patient) as confirmed by RNA fusion panel testing. Pan-TRK IHC was positive in 1 case with TPM3-NTRK1 fusion, equivocal in 1 case with GOLGA4-NTRK3 fusion, and negative in 2 samples with ADAM19-NTRK3 fusion. Our findings show that we were able to successfully identify NTRK fusions that resulted in targeted therapy. However, our results suggest limited sensitivity of pan-TRK IHC for NTRK3 fusions, and that the reduced specificity for pan-TRK IHC in tumors with physiologic or non-specific TRK expression, results in false positive samples that require confirmatory testing by RNA based NGS.

Investigation of discrepant mismatch repair immunohistochemistry and microsatellite instability polymerase chain reaction test results for gynecologic cancers using next-generation sequencing.

Gynecologic cancers are routinely screened for DNA mismatch repair (MMR) gene mutations using immunohistochemistry (IHC) and/or polymerase chain reaction (PCR) for microsatellite instability (MSI) to enable selection of immune checkpoint inhibitor therapy and screen for Lynch syndrome. The limited data that compare IHC and MSI in endometrial tumors have shown discordance rates of 5-10%. We reviewed MMR/MSI results in gynecologic cancers and used next-generation sequencing (NGS) to interrogate discrepancies. Of the 328 cases with both IHC and MSI results, 256 (78.0%) were microsatellite stable (MSS) with preserved MMR (pMMR), 64 (19.5%) cases were MSI-High (MSI-H) with MMR deficient (dMMR), 2 cases showed subclonal loss of MLH1 and PMS2 with MSI-H, and 6 cases were discordant. Overall, there was a 98.2% (322/328) IHC/MSI concordance. Discordant cases were retested and/or subject to NGS. Of the six discrepant cases, five showed dMMR with MSS and one showed pMMR with MSI-H. One dMMR/MSI-L case showed loss of PMS2 with a germline pathogenic mutation. The pMMR/MSI-H case was found to harbor pathogenic variants in MLH1 and MSH6. One of the two cases with subclonal populations demonstrated MSI-H in the dMMR area and MSS in the pMMR area. These results emphasize the importance of selecting the appropriate tumor tissue for both IHC and molecular testing and demonstrate that NGS can help resolve discrepant MMR and MSI results.

Most Frequently Cited Accreditation Inspection Deficiencies for Clinical Molecular Oncology Testing Laboratories and Opportunities for Improvement.

CONTEXT.­: The College of American Pathologists (CAP), a laboratory accreditation organization with deemed status under the Clinical Laboratories Improvement Amendments of 1988 administers accreditation checklists. Checklists are used by laboratories to ensure regulatory compliance. Peer-level laboratory professionals audit laboratory records during inspections to assess compliance. OBJECTIVE.­: To identify the most frequently cited deficiencies for molecular oncology laboratories undergoing CAP accreditation inspections and describe laboratory improvement opportunities. DESIGN.­: The CAP Molecular Oncology Committee (MOC), which is involved in maintaining the Molecular Pathology checklist, reviewed data and inspector comments associated with the most frequently observed citations related to molecular oncology testing from laboratories inspected by the CAP during a 2-year period (2018-2020). RESULTS.­: Of 422 molecular oncology laboratories that underwent accreditation inspections, 159 (37.7%) were not cited for any molecular oncology-related deficiencies. For the All Common (COM) and Molecular Pathology checklists, there were 364 and 305 deficiencies, corresponding to compliance rates of 98.8% and 99.6%, respectively. The most frequently cited deficiencies are described. The COM checklist deficiencies were associated most often with the analytic testing phase; the MOL checklist deficiencies were more evenly distributed across the preanalytic, analytic, and postanalytic phases of testing. CONCLUSIONS.­: Molecular oncology laboratories demonstrated excellent compliance with practices that support high-quality results for patients and the health care providers who use those test results in patient management. This review includes a critical assessment of opportunities for laboratories to improve compliance and molecular oncology testing quality.

Clinical Laboratory Testing Practices in Diffuse Gliomas Prior to Publication of 2021 World Health Organization Classification of Central Nervous System Tumors.

CONTEXT.­: Integration of molecular data into glioma classification supports diagnostic, prognostic, and therapeutic decision-making; however, testing practices for these informative biomarkers in clinical laboratories remain unclear. OBJECTIVE.­: To examine the prevalence of molecular testing for clinically relevant biomarkers in adult and pediatric gliomas through review of a College of American Pathologists proficiency testing survey prior to the release of the 2021 World Health Organization Classification of Central Nervous System Tumors. DESIGN.­: College of American Pathologists proficiency testing 2020 survey results from 96 laboratories performing molecular testing for diffuse gliomas were used to determine the use of testing for molecular biomarkers in gliomas. RESULTS.­: The data provide perspective into the testing practices for diffuse gliomas from a broad group of clinical laboratories in 2020. More than 98% of participating laboratories perform testing for glioma biomarkers recognized as diagnostic for specific subtypes, including IDH. More than 60% of laboratories also use molecular markers to differentiate between astrocytic and oligodendroglial lineage tumors, with some laboratories providing more comprehensive analyses, including prognostic biomarkers, such as CDKN2A/B homozygous deletions. Almost all laboratories test for MGMT promoter methylation to identify patients with an increased likelihood of responding to temozolomide. CONCLUSIONS.­: These findings highlight the state of molecular testing in 2020 for the diagnosis and classification of diffuse gliomas at large academic medical centers. The findings show that comprehensive molecular testing is not universal across clinical laboratories and highlight the gaps between laboratory practices in 2020 and the recommendations in the 2021 World Health Organization Classification of Central Nervous System Tumors.

ALK Gene Rearrangements in Lung Adenocarcinomas: Concordance of Immunohistochemistry, Fluorescence In Situ Hybridization, RNA In Situ Hybridization, and RNA Next-Generation Sequencing Testing.

INTRODUCTION: The 2018 updated molecular testing guidelines for patients with advanced lung cancer incorporated ALK immunohistochemistry (IHC) analysis as an equivalent to fluorescence in situ hybridization (FISH) method recommended in 2013. Nevertheless, no specific recommendation for alternative methods was proposed owing to insufficient data. The aim of this study was to compare the results of ALK IHC, FISH, RNA next-generation sequencing (NGS), and RNA in situ hybridization (ISH) with available clinical data. METHODS: A search for lung carcinomas with ALK testing by greater than or equal to one modality (i.e., ALK IHC, FISH, NGS) was performed; a subset underwent RNA ISH. When available, clinical data were recorded. RESULTS: The results were concordant among all performed testing modalities in 86 of 90 cases (95.6%). Of the four discordant cases, two were ALK positive by FISH but negative by IHC, RNA NGS, and RNA ISH. The remaining two cases failed RNA NGS testing, one was IHC negative, FISH positive, RNA ISH negative and the second was IHC positive, FISH positive, RNA ISH equivocal. RNA NGS identified one rare and one novel ALK fusion. Sufficient therapy data were available in 10 cases treated with tyrosine kinase inhibitors; three had disease progression, including one with discordant results (FISH positive, RNA NGS negative, IHC negative, RNA ISH negative) and two with concordant ALK positivity among all modalities. CONCLUSIONS: Our results reveal high concordance among IHC, RNA NGS, and RNA ISH. In cases of discordance with available RNA NGS, FISH result was positive whereas IHC and ISH results were negative. On the basis of our data, multimodality testing is recommended to identify discrepant results and patients (un)likely to respond to tyrosine kinase inhibitors.

Detection of STRN-ALK fusion in thyroid nodules with indeterminate cytopathology facilitates papillary thyroid cancer diagnosis.

Thyroid cancer is the most common endocrine malignancy. Approximately 70% of cases of papillary thyroid carcinoma and 50% of poorly differentiated and anaplastic thyroid carcinoma harbor well-characterized driver mutations and chromosomal rearrangements that drive tumorigenesis. Molecular profiling has been helpful in identifying and informing follow-up strategies in tumors with more aggressive trajectories. Here, we report a case of papillary thyroid cancer (PTC) discovered in a patient with thyroid nodules with relatively benign ultrasound and fine needle aspiration (FNA) findings. Molecular testing in this patient identified a rare STRN-ALK fusion in two thyroid nodules with indeterminate and/or benign cytology. This led to the patient undergoing a thyroid lobectomy and a subsequent confirmation of papillary thyroid carcinoma upon resection. The report highlights the role of comprehensive molecular testing in thyroid lesions of indeterminate cytology.