Bischoff, Lindsay

ImportanceThyroid cancer incidence has tripled in the past 3 decades, largely driven by increased detection of small, indolent papillary thyroid cancers. Overuse of thyroid ultrasonography (TUS) contributes to overdiagnosis, leading to unnecessary biopsies, procedures, and potential patient harm.ObjectiveTo evaluate the frequency of and factors associated with inappropriate TUS (iTUS) orders and assess related clinical outcomes.Design, Setting, and ParticipantsThis retrospective cohort study analyzed adult patients 18 years and older who underwent their first TUS from January 1, 2017, to December 30, 2021, at 4 Mayo Clinic sites. Patients with previous thyroid nodule, thyroid cancer, thyroid surgery, or TUS were excluded. Based on documented clinical indications, a validated natural language processing model classified TUS orders as appropriate or inappropriate. Data were analyzed from April 2024 to May 2025.ExposuresBaseline characteristics of patients, clinicians, and clinical encounters investigated for their association with an iTUS order.Main Outcomes and MeasuresThe primary outcome was the proportion of iTUS orders. Secondary outcomes included factors associated with iTUS (sociodemographic, clinical, order-specific, and clinician-related factors) and clinical outcomes following iTUS, including the detection of thyroid nodules, thyroid procedures, and thyroid cancer diagnoses.ResultsOf 11 442 included patients, 8422 (73.6%) were female, and the mean (SD) age was 57.3 (15.8) years with a mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) of 29.7 (7.0). Among 11 442 TUS orders, 866 (7.6%) were classified as inappropriate. In multivariable analysis, younger age (age of 18 to 54 years vs older than 65 years; odds ratio [OR], 1.86; 95% CI, 1.56-2.22), hyperthyroidism (OR, 9.04; 95% CI, 6.75-12.11), ordering by nonendocrinology specialties (eg, oncology/hematology; OR, 3.43; 95% CI, 2.47-4.76), and orders not linked to an in-person appointment (eg, portal messages; OR, 2.42; 95% CI, 2.08-2.82) were strongly associated with increased odds of iTUS. Compared with appropriate TUS, iTUS led to lower rates of thyroid nodule detection (202 of 866 [23.3%] vs 6885 of 10 576 [65.1%]; OR, 0.16; 95% CI, 0.14-0.19), biopsies (89 [10.3%] vs 2647 [25.0%]; OR, 0.34; 95% CI, 0.27-0.43), partial thyroidectomies (14 [1.6%] vs 424 [4.0%]; OR, 0.39; 95% CI, 0.23-0.67), and confirmed thyroid cancer cases (16 [1.8%] vs 425 [4.0%]; OR, 0.45; 95% CI, 0.27-0.74).Conclusions and RelevanceIn this cohort study, approximately 1 in 13 TUS orders were inappropriate. iTUS was more common in younger patients, those with thyroid dysfunction, those not seen in person, and in those referred by nonendocrinology specialties. These findings highlight the need for targeted strategies to optimize TUS use and mitigate overdiagnosis and overtreatment.

The NCCN Guidelines for Thyroid Carcinoma address the management of different types of thyroid carcinoma, including papillary, follicular, oncocytic, medullary, and anaplastic carcinoma. The NCCN Thyroid Carcinoma Panel meets at least annually to review comments from reviewers within their institutions, examine relevant new data from publications and abstracts, and reevaluate and update their recommendations. These NCCN Guidelines Insights focus on the panel’s most recent recommendations regarding systemic therapies for thyroid carcinoma as well as the supporting clinical data.

Importance Oncocytic (Hürthle cell) thyroid carcinoma is a follicular cell-derived neoplasm that accounts for approximately 5% of all thyroid cancers. Until recently, it was categorized as a follicular thyroid carcinoma, and its management was standardized with that of other differentiated thyroid carcinomas. In 2022, given an improved understanding of the unique molecular profile and clinical behavior of oncocytic thyroid carcinoma, the World Health Organization reclassified oncocytic thyroid carcinoma as distinct from follicular thyroid carcinoma. The International Thyroid Oncology Group and the American Head and Neck Society then collaborated to review the existing evidence on oncocytic thyroid carcinoma, from diagnosis through clinical management and follow-up surveillance. Observations Given that oncocytic thyroid carcinoma was previously classified as a subtype of follicular thyroid carcinoma, it was clinically studied in that context. However, due to its low prevalence and previous classification schema, there are few studies that have specifically evaluated oncocytic thyroid carcinoma. Recent data indicate that oncocytic thyroid carcinoma is a distinct class of malignant thyroid tumor with a group of distinct genetic alterations and clinicopathologic features. Oncocytic thyroid carcinoma displays higher rates of somatic gene variants and genomic chromosomal loss of heterozygosity than do other thyroid cancers, and it harbors unique mitochondrial DNA variations. Clinically, oncocytic thyroid carcinoma is more likely to have locoregional (lymph node) metastases than is follicular thyroid carcinoma—with which it was formerly classified—and it develops distant metastases more frequently than papillary thyroid carcinoma. In addition, oncocytic thyroid carcinoma rarely absorbs radioiodine. Conclusions and Relevance The findings of this review suggest that the distinct clinical presentation of oncocytic thyroid carcinoma, including its metastatic behavior and its reduced avidity to radioiodine therapy, warrants a tailored disease management approach. The reclassification of oncocytic thyroid carcinoma by the World Health Organization is an important milestone toward developing a specific and comprehensive clinical management for oncocytic thyroid carcinoma that considers its distinct characteristics.

Differentiated thyroid carcinomas is associated with an excellent prognosis. The treatment of choice for differentiated thyroid carcinoma is surgery, followed by radioactive iodine ablation (iodine-131) in select patients and thyroxine therapy in most patients. Surgery is also the main treatment for medullary thyroid carcinoma, and kinase inhibitors may be appropriate for select patients with recurrent or persistent disease that is not resectable. Anaplastic thyroid carcinoma is almost uniformly lethal, and iodine-131 imaging and radioactive iodine cannot be used. When systemic therapy is indicated, targeted therapy options are preferred. This article describes NCCN recommendations regarding management of medullary thyroid carcinoma and anaplastic thyroid carcinoma, and surgical management of differentiated thyroid carcinoma (papillary, follicular, Hürthle cell carcinoma).