Cutaneous fistula formation after thyroid nodule rupture: A rare complication after radiofrequency ablation.

BACKGROUND: With innovative treatment options such as radiofrequency ablation (RFA) for thyroid nodules, new complications are being identified. It is important to define and delineate complications in order to counsel patients appropriately about treatment options and their associated risks and benefits. METHODS: A 46-year-old male presented with a left thyroid nodule (6.5 cm). Fine needle aspiration results were benign. He started to develop intermittent dyspnea and underwent one RFA procedure. Approximately 6 days post-RFA, the neck area was raised and red with blister. The skin overlying the blister underwent eventual dehiscence with fluid spillage. Several months later, MRI imaging showed substernal extension with tracheal deviation. RESULTS: A left thyroid lobectomy was performed with cutaneous excision and successful closure of a fistula. CONCLUSIONS: This is the first reported case of a thyroid nodule rupture following RFA which manifested into a thyro-cutaneous fistula and required surgical intervention.

Malpractice Trends Involving Active Surveillance Across Cancers.

OBJECTIVE: To characterize malpractice trends related to active surveillance (AS) as a treatment strategy across cancers. BACKGROUND: Active surveillance is increasingly considered a viable management strategy for low-risk cancers. Since a subset of AS cases will progress, metastasize, or exhibit cancer-related mortality, a significant barrier to implementation is the perceived risk of litigation from missing the window for cure. Data on malpractice trends across cancers are lacking. METHODS: Westlaw Edge and LexisNexis Advance databases were searched from 1990 to 2022 for malpractice cases involving active surveillance in conjunction with thyroid cancer, prostate cancer, kidney cancer, breast cancer, or lymphoma. Queries included unpublished cases, trial orders, jury verdicts, and administrative decisions. Data were compiled on legal allegations, procedures performed, and verdicts or settlements rendered. RESULTS: Five prostate cancer cases were identified that pertained to active surveillance. Two cases involved alleged deliberate indifference from AS as a management strategy but were ruled as following the appropriate standard of care. In contrast, 3 cases involved alleged physician negligence for not explicitly recommending AS as a treatment option after complications from surgery occurred. All cases showed documented informed consent for AS, leading to defense verdicts in favor of the physicians. No cases of AS-related malpractice were identified for other cancer types. CONCLUSIONS: To date, no evidence of successful malpractice litigation for active surveillance in cancer has been identified. Given the legal precedent detailed in the identified cases and increasing support across national guidelines, active surveillance represents a sound management option in appropriate low-risk cancers, with no increased risk of medicolegal exposure.

Expanded Parameters in Active Surveillance for Low-risk Papillary Thyroid Carcinoma: A Nonrandomized Controlled Trial.

Importance: Unlike for prostate cancer, active surveillance for thyroid cancer has not achieved wide adoption. The parameters by which this approach is feasible are also not well defined, nor is the effect of patient anxiety. Objective: To determine if expanded size/growth parameters for patients with low-risk thyroid cancer are viable, as well as to assess for cohort differences in anxiety. Design, Setting, and Participants: This prospective nonrandomized controlled trial was conducted at a US academic medical center from 2014 to 2021, with mean [SD] 37.1 [23.3]-month follow-up. Of 257 patients with 20-mm or smaller Bethesda 5 to 6 thyroid nodules, 222 (86.3%) enrolled and selected treatment with either active surveillance or immediate surgery. Delayed surgery was recommended for size growth larger than 5 mm or more than 100% volume growth. Patients completed the 18-item Thyroid Cancer Modified Anxiety Scale over time. Interventions: Active surveillance. Main Outcomes and Measures: Cumulative incidence and rate of size/volume growth. Results: Of the 222 patients enrolled, the median (IQR) age for the study population was 46.8 (36.6-58) years, and 76.1% were female. Overall, 112 patients (50.5%) underwent treatment with active surveillance. Median tumor size was 11.0 mm (IQR, 9-15), and larger tumors (10.1-20.0 mm) comprised 67 cases (59.8%). One hundred one (90.1%) continued to receive treatment with active surveillance, 46 (41.0%) had their tumors shrink, and 0 developed regional/distant metastases. Size growth of more than 5 mm was observed in 3.6% of cases, with cumulative incidence of 1.2% at 2 years and 10.8% at 5 years. Volumetric growth of more than 100% was observed in 7.1% of cases, with cumulative incidence of 2.2% at 2 years and 13.7% at 5 years. Of 110 patients who elected to undergo immediate surgery, 21 (19.1%) had equivocal-risk features discovered on final pathology. Disease severity for all such patients remained classified as stage I. Disease-specific and overall survival rates in both cohorts were 100%. On multivariable analysis, immediate surgery patients exhibited significantly higher baseline anxiety levels compared with active surveillance patients (estimated difference in anxiety scores between groups at baseline, 0.39; 95% CI, 0.22-0.55; P < .001). This difference endured over time, even after intervention (estimated difference at 4-year follow-up, 0.50; 95% CI, 0.21-0.79; P = .001). Conclusions and Relevance: The results of this nonrandomized controlled trial suggest that a more permissive active surveillance strategy encompassing most diagnosed thyroid cancers appears viable. Equivocal-risk pathologic features exist in a subset of cases that can be safely treated, but suggest the need for more granular risk stratification. Surgery and surveillance cohorts possess oppositional levels of worry, elevating the importance of shared decision-making when patients face treatment equivalence. Trial Registration: ClinicalTrials.gov Identifier: NCT02609685.

Case Report of CCDC149-ALK Fusion: A Novel Genetic Alteration and a Clinically Relevant Target in Metastatic Papillary Thyroid Carcinoma.

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer, usually with an indolent course. ALK fusions are rare in PTC but may give rise to a more aggressive behavior. We report a novel ALK fusion, CCDC149-ALK, not previously described in PTC, detected by next-generation sequencing in a 30-year-old woman with progressive widely metastatic radioiodine-refractory (RAIR) disease to lung, muscle, and brain. The patient was started on alectinib, a second-generation anaplastic lymphoma kinase (ALK) inhibitor. Within eight weeks, her palpable disease had completely regressed, and the serum thyroglobulin decreased dramatically. Restaging imaging demonstrated an objective partial response. Our case highlights the role of ALK fusions in thyroid cancer and highlights its clinical significance in PTC. We recommend deep mutational sequencing in BRAFV600E-negative RAIR PTC to identify targetable genetic alterations, including gene fusions, that may result in dramatic therapeutic benefits.

Predictive Impact of Metastatic Lymph Node Burden on Distant Metastasis Across Papillary Thyroid Cancer Variants.

Background: While numerous factors determine prognosis in papillary thyroid carcinoma (PTC), distant metastasis (M1) represents one of the most dire. Escalating nodal burden and aggressive histology may contribute to higher metastatic risk, but this relationship is poorly defined and challenging to anticipate. We evaluate the predictive impact of these histological features on predicting distant metastases at initial presentation. Methods: Univariate and multivariable logistic regression models of conventional and aggressive thyroid cancer variants (well-differentiated papillary thyroid carcinoma [WDPTC], diffuse sclerosing variant [DSV], tall cell variant [TCV], poorly differentiated thyroid cancer [PDTC], and anaplastic thyroid carcinoma [ATC]) identified via U.S. cancer registry data were constructed to determine associations between M1 status and quantitative nodal burden. Associations between metastatic lymph node (LN) number and M1 disease were modeled using univariate and multivariable logistic regression with interaction terms, as well as a linear continuous probability model. Results: Overall, M1 prevalence at disease presentation was 3.6% (n = 1717). When stratified by subtype, M1 prevalence varied significantly by histology (WDPTC [1.0%], DSV [2.3%], TCV [4.1%], PDTC [17.4%], ATC [38.4%] [p < 0.001]). For WDPTC, M1 prevalence escalated with metastatic LN number (0 LN+ [0.5%], 1-5 LN+ [2.0%], 6-10 LN+ [3.4%], >10 LN+ [5.5%] [p < 0.001]) and LN ratio (p < 0.001). A statistically significant interaction was observed between histology and increasing nodal burden for M1 risk. On multivariable analysis, each successive metastatic LN conferred increased M1 risk for WDPTC (odds ratio [OR] 1.06 [1.05-1.08], p < 0.001) and TCVs (OR 1.04 [1.02-1.07], p < 0.001). In contrast, other aggressive variants had a higher baseline M1 risk, but this did not vary based on the number of positive LN (DSV, OR 1.02 [0.95-1.10], p = 0.52; PDTC, OR 1.00 [0.98-1.02], p = 0.66; ATC, 1.00 [0.98-1.02], p = 0.97). Conclusions: Progressive nodal burden independently escalates the risk of distant metastasis in WDPTC and TCVs of PTC. Conversely, aggressive variants such as PDTC and ATC have substantial M1 risk at baseline and appear to be minimally affected by metastatic nodal burden. Consideration of these factors after surgery may help tailor clinical decision-making for treatment and surveillance. Further studies are warranted to calibrate the ideal management approach for these higher risk patient groups.

Incidental parathyroidectomy in thyroidectomy and central neck dissection.

BACKGROUND: Although higher thyroidectomy volume has been linked with lower complication rates, its association with incidental parathyroidectomy remains less studied. The volume relationship is even less clear for central neck dissection, where individual parathyroid glands are at greater risk. METHODS: Patients undergoing thyroidectomy with or without central neck dissection were evaluated for incidental parathyroidectomy, hypoparathyroidism, and hypocalcemia. Univariate and multivariable analyses were performed using binary logistic regression. RESULTS: Overall, 1,114 thyroidectomies and 396 concurrent central neck dissections were performed across 7 surgeons. Incidental parathyroidectomy occurred in 22.4% of surgeries (range, 16.9%-43.6%), affecting 7.1% of parathyroids at risk (range, 5.8%-14.5%). When stratified by surgeon, lower incidental parathyroidectomy rates were associated with higher thyroidectomy volumes (R2 = 0.77, P = .008) and higher central neck dissection volumes (R2 = 0.93, P < .001). On multivariable analysis, low-volume surgeon (odds ratio 2.94, 95% confidence interval 2.06-4.19, P < .001), extrathyroidal extension (odds ratio 3.13, 95% confidence interval 1.24-7.87, P = .016), prophylactic central neck dissection (odds ratio 2.68, 95% confidence interval 1.65-4.35, P <.001), and therapeutic central neck dissection (odds ratio 4.44, 95% confidence interval 1.98-9.96, P < .001) were the most significant factors associated with incidental parathyroidectomy. In addition, incidental parathyroidectomy was associated with a higher likelihood of temporary hypoparathyroidism (odds ratio 2.79, 95% confidence interval 1.45-5.38, P = .002) and permanent hypoparathyroidism (odds ratio 4.62, 95% confidence interval 1.41-5.96, P = .025), but not permanent hypocalcemia (odds ratio 1.27, 95% confidence interval 0.48-3.35, P = .63). Higher lymph node yield in central neck dissection was not associated with higher incidental parathyroidectomy rates (odds ratio 1.13, 95% confidence interval 0.85-8.81, P = .82). CONCLUSION: Higher surgical volume conferred a lower rate of incidental parathyroidectomy. Nonetheless, greater lymph node yield in central neck dissections did not result in greater parathyroid-related morbidity. Such findings support the value of leveraging surgical volume to both optimize oncologic resection and minimize complication rates.

The Masquerading, Masculinizing Tumor: A Case Report and Review of the Literature.

Androgen-producing tumors in women are rare neoplasms that can cause secondary virilizing characteristics. Of patients presenting with symptoms of hyperandrogenism, these tumors are found in ∼0.2% of cases. Androgen-producing tumors can arise from the ovary or the adrenal gland. Those arising from the ovary are rare, accounting for <5% of all ovarian tumors. This case presents a hilar Leydig cell tumor of the ovary, which resulted in secondary virilization of a 45-year-old female 2 months after cessation of combined oral contraceptives (COC). Laboratory findings showed markedly elevated total and free testosterone concentrations with normal dehydroepiandrosterone sulfate, however neither pelvic ultrasound nor magnetic resonance imaging demonstrated any masses. Venous sampling under fluoroscopy revealed supraphysiologic testosterone concentrations from the right ovarian vein suggesting the source. The patient underwent bilateral salpingo-oophorectomy revealing a 1.3 cm hilar cell tumor of the right ovary. This article reviews the clinical features, diagnosis, and treatment of hilar Leydig cell tumors and describes the long-term complications of supraphysiologic testosterone levels. As the tumor presented after cessation of COC, we also review the mechanisms by which COC might suppress supraphysiologic androgen levels and mask the secondary virilizing effects of androgen-producing tumors.

Prognostic Impact of Histologic Grade for Papillary Thyroid Carcinoma.

BACKGROUND: While numerous factors affect prognosis in papillary thyroid carcinoma (PTC), the comparative impact of histologic grade has not been well described. Moreover, indications for external beam radiation therapy (EBRT) remain imprecise. We evaluate clinicopathologic characteristics and outcomes for PTC stratified by grade. METHODS: We profiled histologic grade for PTC (well differentiated, moderately differentiated, poorly differentiated) via hospital (National Cancer Database) and population-based (Surveillance, Epidemiology, and End Results) registries. Cox regression was used to adjust for clinicopathologic covariates. Statistical interactions between subtypes and the effect of EBRT on survival were assessed. RESULTS: Collectively, worsening clinicopathologic factors (age, tumor size, extrathyroidal extension, nodal spread, M1 disease) and outcomes (disease-free survival, overall survival) correlated with less differentiated state, across all histologic grades (p < 0.001). Multivariable analysis showed escalating hazard with loss of differentiation relative to well-differentiated PTC (moderately differentiated hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.04-1.41, p = 0.02; poorly differentiated HR 2.62, 95% CI 2.23-3.08, p < 0.001). Correspondingly, greater survival benefit was associated with EBRT for poorly differentiated cases (HR 0.36, 95% CI 0.18-0.72, p = 0.004). This finding was upheld after landmark analysis to address potential immortal time bias (HR 0.37, 95% CI 0.17-0.80, p = 0.01). CONCLUSIONS: Worsening histologic grade in PTC is independently associated with parallel escalation in mortality risk, on a scale approximating or surpassing established thyroid cancer risk factors. On preliminary analysis, EBRT was associated with improved survival in the most aggressive or least differentiated subvariants. Further investigation is warranted to examine the efficacy of EBRT for select poorly differentiated thyroid carcinomas.

Cost-effectiveness of fiberoptic laryngoscopy prior to total thyroidectomy for low-risk thyroid cancer patients.

BACKGROUND: Flexible fiberoptic laryngoscopy is performed prior to thyroid surgery to evaluate the function of the recurrent laryngeal nerve. We assess the cost-effectiveness of preoperative laryngoscopy prior to total thyroidectomy for a low-risk thyroid cancer patient without dysphonia. METHODS: A decision tree analysis was performed from a third-party payer perspective. We assessed the cost-effectiveness of fiberoptic laryngoscopy prior to total thyroidectomy for T2N0M0 papillary thyroid carcinoma, such that an ipsilateral vocal fold paralysis alters the surgical plan to hemi-thyroidectomy, when permissible, to avoid the risk of bilateral vocal fold paralysis. RESULTS: Performing preoperative laryngoscopy to assess vocal fold function has an incremental cost-effectiveness ratio (ICER) of 45 193 USD/QALY compared to no laryngoscopy. At a willingness-to-pay of 100 K/QALY, the intervention is cost-effective if the incidence of vocal fold paralysis is at least 0.57%, or when the permissible rate of hemithyroidectomy in cases of incidental paralysis is at least 41%. Probabilistic sensitivity analysis shows that laryngoscopy is cost-effective in 90.9% of cases. CONCLUSIONS: Fiberoptic laryngoscopy is a cost-effective prior to total thyroidectomy in asymptomatic, low-risk thyroid cancer patients.

Crowdfunding Campaigns and Thyroid Surgery: Who, What, Where, and How Much?

BACKGROUND: Crowdfunding has become a unique response to the challenge of health care expenses, yet it has been rarely studied by the medical community. We looked to describe the scope of crowdfunding in thyroid surgery and analyze the factors that contribute toward a successful campaign. METHODS: In November 2018, active campaigns were retrieved from a popular crowdfunding Web site using search terms thyroidectomy and thyroid surgery and filtered to include only campaigns that originated in the United States. RESULTS: About 1052 thyroid surgery-related campaigns were analyzed. About 836 (79.5%) involved female patients and 43 (4.1%) pediatric patients. About 792 campaigns (75.3%) referred to thyroid cancer as a primary condition, 163 (15.5%) benign thyroid disease, and 97 (9.2%) other conditions. The average amount raised per campaign was $2514.54 (range, $0-$53,160). About 338 (32.1%) campaigns were self-posted, 317 (30.1%) posted by family, and 397 (37.7%) posted by friends. Median campaign duration was 20 mo, with a median number of 16 donors, 17 hearts, and 136 social media shares. Campaigns related to thyroid cancer raised more funds ($2729.97) than benign ($1669.84) or other ($2175.03) conditions (P < 0.001). Campaigns submitted by friends ($3524.78) received more funding than those by self ($1672.48) or family ($2147.19) (P < 0.001). Campaign duration, donor number, share number, and hearts were also significant predictors of amount raised. CONCLUSIONS: For thyroid surgery-related crowdfunding, campaigns referring to thyroid cancer had the highest amount of funds raised. Campaigns created by friends and other factors related to increased community engagement such as social media shares were also related to increased funds.

Incidence and Mortality Risk Spectrum Across Aggressive Variants of Papillary Thyroid Carcinoma.

Importance: While well-differentiated papillary thyroid carcinoma (WDPTC) outcomes have been well characterized, the prognostic implications of more aggressive variants are far less defined. The rarity of these subtypes has led to their consolidation as intermediate risk for what are in fact likely heterogeneous diseases. Objective: To analyze incidence, clinicopathologic characteristics, and outcomes for aggressive variants of papillary thyroid carcinoma (PTC). Design, Setting, and Participants: This cohort study used data from 2000 to 2016 from hospital-based and population-based US cancer registries to analyze aggressive PTC variants, including diffuse sclerosing (DSV), tall-cell (TCV), insular, and poorly differentiated (PDTC) subtypes. These variants were compared against WDPTC and anaplastic cases. Data analysis was conducted from January 2019 to October 2019. Main Outcomes and Measures: Age-adjusted incidence was calculated via annual percentage change (APC) using the weighted least-squares method. Overall survival and disease-specific survival were analyzed via Cox regression. Propensity-score matching was used to adjust survival analyses for clinical and demographic covariates. Results: Collectively, 5447 aggressive PTC variants were identified (including 415 DSV, 3339 TCV, 362 insular, and 1331 PDTC cases), as well as 35 812 WDPTC and 2249 anaplastic cases. Over the study period, a substantial increase in aggressive variant incidence was observed (APC, 9.1 [95% CI, 7.33-10.89]; P < .001), surpassing the relative increases observed in WDPTC (APC, 5.1 [95% CI, 3.98-6.12]; P < .001) and anaplastic cases (APC, 1.9 [95% CI, 0.75-3.05]; P = .003; parallelism P < .007). Survival varied markedly based on histologic subtype, with a wide spectrum of mortality risk noted; 10-year overall survival was 85.4% (95% CI, 84.6%-86.3%) in WDPTC, 79.2% (95% CI, 73.6%-85.3%) in DSV, 71.9% (95% CI, 68.4%-75.6%) in TCV, 45.1% (95% CI, 40.2%-50.6%) in PDTC, 27.9% (95% CI, 20.0%-38.9%) in the insular variant, and 8.9% (95% CI, 7.5%-10.6%) in anaplastic cases (P < .001). These differences largely persisted even after adjusting for inherent differences in baseline characteristics by multivariable Cox regression and propensity-score matching. Conclusions and Relevance: An upsurge in aggressive PTC incidence was observed at a rate beyond that seen in WDPTC or anaplastic thyroid carcinoma. Moreover, long-term survival outcomes for aggressive PTC subgroups exhibit heterogeneous clinical behavior and a wide range of mortality risk, suggesting that treatment should be tailored to specific histologic subtypes. Given increasing prevalence and disparate outcomes, further investigation to identify optimal therapeutic strategies is needed in these diverse, understudied populations.

Symptomatic Cervical Tumoral Calcinosis due to Cosmetic Body Contouring Mineral Oil Injections.

Tumoral calcinosis (TC) is an uncommon disease that has been linked to familial genetic mutations but can often be due to secondary causes such as chronic renal failure and hyperparathyroidism. There are rare instances of tumoral calcinosis induced by foreign body injections, often for cosmetic purposes. Here we describe operative management of spinal cord compression due to mineral oil injection induced tumoral calcinosis. A 54-year-old transgender female presented with signs of myelopathy so severe that she had become wheelchair bound. Labs demonstrated hypercalcemia and imaging of the neuroaxis revealed significant calcification resulting in cervicothoracic and lumbar central canal stenosis. Given symptomatic cervical spinal cord compression, she was taken to the OR for urgent laminectomy and decompression. Postoperatively, she recovered well and was ambulating independently by postoperative day (POD) 9. This is the first reported case of localized mineral oil injections causing distant calcification with subsequent symptomatic cord compression requiring operative intervention.

Papillary thyroid microcarcinoma: optimal management versus overtreatment.

PURPOSE OF REVIEW: The treatment of small, low-risk papillary thyroid carcinoma has undergone a paradigm shift, with many tumors now initially treated with active surveillance rather than upfront surgery. Further studies on patients enrolled in active surveillance have refined our knowledge of the clinical behavior of papillary thyroid microcarcinomas. RECENT FINDINGS: This article summarizes the major conclusions of landmark trials that launched active surveillance as a viable treatment option for selected patients. We discuss patient factors such as age and tumor size, the assessment of candidates for active surveillance, barriers to acceptance of active surveillance, quality of life issues, and economic considerations. SUMMARY: Active Surveillance is a viable first-line treatment option for select papillary microcarcinomas.

Mortality Risk of Nonoperative Papillary Thyroid Carcinoma: A Corollary for Active Surveillance.

Background: Active surveillance is established as an alternative to surgery for papillary thyroid microcarcinomas, but inclusion criteria and mortality risk for pursuing a nonsurgical approach have not been clearly defined. To gauge the feasibility of expanding active surveillance thresholds, we investigated the effects of increasing size and age on disease-specific survival (DSS) in a large nonoperative thyroid cancer cohort, compared against a matched group of surgical patients. Methods: Papillary thyroid carcinoma patients staged T1-4N0M0 were identified in the Surveillance, Epidemiology, and End Results (SEER) database between 1975 and 2015, stratified by nonsurgical and surgical management. Propensity score matching was performed to adjust for imbalances in covariates. Multivariable models were constructed using restricted cubic splines to model nonlinear relationships of age and tumor size with DSS. Results: Overall, 1453 nonoperative patients and 54,718 surgical patients met the inclusion criteria. Collectively, increasing age and size after certain thresholds independently led to greater differences in DSS between nonsurgical and surgical patients. For younger ages (14-55 years), surgical approach compared with nonsurgical approach was not associated with any difference in the 10-year DSS among 0-4 cm cancers (99.8% vs. 100%, p = 0.470), 4.1-6 cm cancers (98.8% vs. 100%, p = 0.599), or >6 cm cancers (97.3% vs. 100%, p = 0.718). Older patients with larger tumors (>75 years, >6 cm) demonstrated the greatest difference in DSS (48.1% vs. 91.3%, p < 0.001). Similar results were found when applying propensity score matching. For age, restricted cubic spline plots showed minimal relative survival hazard in nonoperative cases beginning after age 60 years, with a change point illustrating acceleration in relative hazard beyond age 72 years. For size, relative survival hazard was observed after 2.0 cm and increased slowly with nodule growth up to an inflection point of 4.5 cm. Beyond this, mortality risk escalated with each additional year without plateau. Conclusions: Increasing age and size lead to progressively greater mortality risk without surgery, but only beyond certain thresholds. We define escalating gradients at which a nonsurgical approach may be deemed appropriate, and beyond which survival benefits from surgery become apparent. Such findings reconcile controversial observations regarding age and size in active surveillance and further reshape evolving treatment paradigms in thyroid cancer.

Update on Molecular Testing for Cytologically Indeterminate Thyroid Nodules.

Fine needle aspiration biopsy (FNAB) and ultrasonography are the most common modalities for the diagnosis and follow up of thyroid nodules. FNAB is able to distinguish benign from malignant nodules with high sensitivity and specificity; however, 20% to 30% of nodules are diagnosed as indeterminate with a risk of malignancy varying from 10% to 75% based on the 2017 revision of the Bethesda System for Reporting Thyroid Cytopathology. Molecular tests are being increasingly used to triage this group of nodules. Several molecular tests are commercially available and newer upgrades are being developed to either "rule in" or "rule out" malignancy with greater accuracy. The Afirma gene expression classifier and its recent upgrade (the Afirma gene sequencing classifier), Thryoseq v2, a next generation sequencing test and its recent upgrade (the v3), RosettaGX Reveal based on microRNA alterations, and ThyGenX/ThyraMIR, a combination test, are currently on the market. Familiarity with these tests, their performance, and postvalidation publications will enable appropriate test selection and improve triage of patients for appropriate therapy. The underlying rate of malignancy at different institutions and the interobserver variability in cytologic and histologic diagnosis of thyroid lesions are important factors that impact the performance of the various molecular tests.

Interinstitutional variation in predictive value of the ThyroSeq v2 genomic classifier for cytologically indeterminate thyroid nodules.

BACKGROUND: The ThyroSeq v2 next-generation sequencing assay estimates the probability of malignancy in indeterminate thyroid nodules. Its diagnostic accuracy in different practice settings and patient populations is not well understood. METHODS: We analyzed 273 Bethesda III/IV indeterminate thyroid nodules evaluated with ThyroSeq at 4 institutions: 2 comprehensive cancer centers (n = 98 and 102), a multicenter health care system (n = 60), and an academic medical center (n = 13). The positive and negative predictive values of ThyroSeq and distribution of final pathologic diagnoses were analyzed and compared with values predicted by Bayes theorem. RESULTS: Across 4 institutions, the positive predictive value was 35% (22%-43%) and negative predictive value was 93% (88%-100%). Predictive values correlated closely with Bayes theorem estimates (r2 = 0.84), although positive predictive values were lower than expected. RAS mutations were the most common molecular alteration. Among 84 RAS-mutated nodules, malignancy risk was variable (25%, range 10%-37%) and distribution of benign diagnoses differed across institutions (adenoma/hyperplasia 12%-85%, noninvasive follicular thyroid neoplasm with papillary-like nuclear features 5%-46%). CONCLUSION: In a multi-institutional analysis, ThyroSeq positive predictive values were variable and lower than expected. This is attributable to differences in the prevalence of malignancy and variability in pathologist interpretations of noninvasive tumors. It is important that clinicians understand ThyroSeq performance in their practice setting when evaluating these results.