The 'Thyroid: Year in Review', presented at the AACE 2026 annual meeting, synthesized practice-influencing peer-reviewed clinical research published between March 1, 2025, and February 15, 2026. This narrative review, based on that presentation, highlights two overarching themes in clinical thyroidology: precision medicine and de-escalation when appropriate. In thyroid dysfunction, recent studies support lean body mass-based levothyroxine dosing and the metabolic integration of liothyronine. The management of thyroid nodules and differentiated thyroid cancer has shifted toward de-escalation, favoring non-surgical interventions, active surveillance for low-risk malignancies, selective omission of radioactive iodine, de-escalation of surveillance strategies, and the complementary use of artificial intelligence with molecular testing to improve diagnostic accuracy in indeterminate nodules. This review summarizes these findings and their implications for contemporary evidence-based endocrine practice.

Thyroid nodules are frequently encountered during carotid Doppler ultrasonography, yet their clinical significance remains uncertain. This prospective study evaluated the prevalence, management, and clinical yield of thyroid nodules detected during opportunistic thyroid assessment performed alongside carotid Doppler examinations. A total of 510 consecutive adult patients were enrolled between November 2025 and May 2026. Thyroid nodules were classified according to the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS). Follow-up recommendations, fine-needle aspiration biopsy (FNAB) rates, cytopathological outcomes, and biopsy adherence were analyzed. Thyroid nodules were detected in 338 patients (66.3%). Follow-up ultrasonography was recommended in 58 patients (17.2%), and FNAB was recommended in 37 (11.0%). Biopsy was performed in 21 patients (56.8%). Three malignancies were identified, yielding an overall malignancy rate of 0.6% (3/510). Patients who did not undergo recommended biopsy were significantly older than those who underwent biopsy (P=0.032), and biopsy adherence was lower among rural residents (P=0.039). Although thyroid nodules were highly prevalent, the overall malignancy yield was low. An ACR TI-RADS-guided selective reporting strategy may reduce unnecessary investigations while maintaining detection of clinically significant thyroid cancer.

Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) has become increasingly integrated into prostate cancer staging and restaging. PSMA expression, however, is not restricted to prostatic tissue and may be detected in several non-prostatic malignancies, including thyroid carcinoma. We report the case of a male patient with very high-risk acinar prostate adenocarcinoma (Gleason score 4+4) who underwent whole-body 18F-PSMA-1007 PET/CT for staging purposes. The patient was classified as very high-risk according to NCCN (National Comprehensive Cancer Network) criteria and was managed with androgen deprivation therapy, radiotherapy, and salvage radical prostatectomy. Imaging demonstrated a focal PSMA-avid hypodense nodule in the right thyroid lobe, measuring 15 mm with a maximum standardized uptake value (SUVmax) of 6.33. Subsequent neck ultrasonography (TI-RADS 4) and fine-needle aspiration biopsy confirmed papillary thyroid carcinoma (Bethesda category VI). The patient underwent a total thyroidectomy with a level VI central neck dissection. Histopathological examination revealed multifocal papillary thyroid carcinoma with focal vascular invasion involving three vessels and central compartment nodal metastasis (pT1bN1a). Following surgery and radioactive iodine ablation with 150 mCi of iodine-131, the patient achieved an excellent biochemical response, with thyroglobulin becoming undetectable under TSH (thyroid-stimulating hormone) suppression and no evidence of structural recurrence on follow-up imaging. This case highlights the clinical relevance of incidental focal thyroid uptake detected on PSMA PET/CT performed for prostate cancer staging. Incidental PSMA-avid thyroid lesions may occasionally identify biologically significant synchronous malignancies and should prompt dedicated evaluation with ultrasonography and fine-needle aspiration when clinically appropriate.

Background Fine-needle aspiration cytology (FNAC) and fine-needle non-aspiration cytology (FNNAC) are commonly used techniques for the evaluation of thyroid lesions. Differences in smear quality, cellular preservation, and diagnostic performance between these methods remain a subject of interest. Our study compared FNAC and FNNAC in thyroid lesions using histopathological examination as the reference standard. Methodology A cross-sectional observational study was conducted among 110 patients with clinically palpable thyroid swellings, of whom 75 patients who underwent thyroid surgery with available histopathological examination were included in the final analysis. Both FNAC and FNNAC were performed on the same lesion during the same sitting. Smears were assessed for adequacy, cellular preservation, and diagnostic categorization using the Bethesda System for Reporting Thyroid Cytopathology. Histopathological examination served as the reference standard for cytohistological correlation and assessment of diagnostic performance. Results The mean age of participants was 42.88 ± 13.59 years. Superior smear quality was observed in 55 (73.3%) FNAC samples and 59 (78.7%) FNNAC samples. Bethesda Category II lesions constituted the majority of cases with both techniques. FNNAC reduced the proportion of indeterminate lesions and identified a higher proportion of malignant lesions. Histopathology revealed 53 (70.7%) benign and 22 (29.3%) malignant lesions. FNNAC demonstrated a stronger correlation with histopathological diagnosis and showed better preservation of cellular architecture with less blood contamination. Diagnostic accuracy was numerically higher with FNNAC (63, 84.0%) than with FNAC (58, 77.3%), with corresponding sensitivities of 11 (50.0%) and 9 (40.9%), respectively; however, the difference in diagnostic accuracy was not statistically significant (McNemar's test, p = 0.228). Conclusions Both FNAC and FNNAC are effective techniques for the cytological evaluation of thyroid lesions. FNNAC demonstrated higher smear quality, improved cellular preservation, higher specificity, and numerically higher overall diagnostic accuracy than FNAC. Although the difference in diagnostic accuracy was not statistically significant, FNNAC may serve as a valuable alternative or complementary technique for improving smear quality in thyroid cytology.

Accurately distinguishing the benign thyroid nodules (BTNs) and malignant thyroid nodules (MTNs) is crucial for treatment planning and prognosis. This study aims to explore the clinical value of artificial intelligence ultrasound-assisted diagnostic system (AI-UADS) in diagnosing the BTNs and MTNs. In this retrospective case-control study, a total of 161 TNs from 91 patients confirmed by surgical pathology were included. All nodules underwent ultrasound examinations and were evaluated by both senior ultrasonographers and AI-UADS, independently. Using surgical pathology as the gold standard, the diagnostic performance of the 2 methods was analyzed using receiver operating characteristic curves (including classify the nodules based on size, location, capsule relationships, and presence or absence of Hashimoto thyroiditis [HT]). The area under the curve, accuracy, sensitivity, specificity, positive predictive value and negative predictive value of AI-UADS in the differential diagnosis of BTNs and MTNs were 0.933, 93.2%, 92.4%, 94.2%, 95.5%, and 90.3%, respectively, all of which were higher than ultrasonographers (0.821, 82.0%, 81.5%, 82.6%, 86.2%, and 77.0%, respectively) (all P < .05). Specifically, the accuracy in diagnosing nodules with a maximum diameter ≤10 mm (94.0% vs 80.7%) and in the left lobe (92.5% vs 81.3%); the accuracy, sensitivity, specificity, positive predictive value and negative predictive value in diagnosing nodules with far from the capsule ([93.8% vs 79.5%], [92.5% vs 75.5%], [94.9% vs 83.1%], [94.2% vs 80.0%], [93.3% vs 79.0%]) and without HT ([94.0% vs 82.7%], [93.2% vs 82.4%], [94.9% vs 83.1%], [95.8% vs 85.9%], [91.8% vs 79.0%]) of AI-UADS were higher than ultrasonographers (all P < .05). The AI-UADS demonstrates good diagnostic performance in differentiating BTNs and MTNs, and can serve as an effective auxiliary tool for ultrasonographers. It shows particular advantages in diagnosing nodules with a maximum diameter ≤10 mm, located in the left lobe, far from the capsule, and in patients without HT.

Thyroid nodules and goiter remain common conditions affecting healthy child development, attributable to diagnostic advances and environmental-genetic interactions. However, pediatric etiology research remains limited. A total of 997 children aged 8 to 10 years were recruited from iodine-adequate areas across 13 districts in Tianjin, China. Venous blood was collected for genotyping three single nucleotide polymorphisms (thyroid stimulating hormone receptor (TSHR) rs2268458, thyroid transcription factor 1 (TTF1) rs2076735 and phosphodiesterase 8B (PDE8B) rs4704397) using Sequenom MassARRAY. Data on up to 30 potential external factors were also collected. The detection rates of thyroid nodules and goiter were 23.57% and 8.83%, respectively. Gender, higher body surface area (BSA) (Q4: >1.30 m[2]), and living in a multistory building increased thyroid nodules risk (P < 0.05). Older children had higher goiter risk (P = 0.001), whereas higher BSA (Q3: 1.18-1.30 m[2]; Q4: >1.30 m[2]) and mothers with stable jobs reduced goiter risk (P < 0.05). In genotype-stratified analyses, TSHR, TTF1, and PDE8B polymorphisms appeared to moderate associations between multiple external factors (gender, BSA, urinary iodine, stress, anxiety) and thyroid nodules or goiter (P < 0.05), although no significant gene-environment interactions were detected in the overall models. Notably, among children with specific genotypes, certain factors that were not statistically significant in the full multivariable model, including urinary iodine with thyroid nodules and stress and anxiety with goiter, showed substantially strengthened associations. Multiple external factors are associated with thyroid nodules and goiter in children. Polymorphisms in TSHR rs2268458, TTF1 rs2076735, and PDE8B rs4704397 may modulate the effects of various external factors on childhood thyroid nodules and goiter.

The synchronous occurrence of papillary thyroid carcinoma (PTC) and chronic lymphocytic leukemia (CLL) is rare and poses diagnostic challenges, particularly in distinguishing metastatic thyroid disease from hematological lymphadenopathy. The present report documents the case of a 64-year-old female patient with long-standing CLL who presented with a malignant thyroid nodule accompanied by multiple enlarged cervical lymph nodes. A diagnosis was established through integrated immunohistochemistry, flow cytometry and multimodal imaging. After the diagnosis of synchronous PTC and CLL/SLL was confirmed, the patient underwent a total thyroidectomy with central compartment lymph node dissection. In addition, a focused review of the literature was conducted to contextualize the clinical presentation, diagnostic strategies and management approaches. Treatment and follow-up were guided by a multidisciplinary team. No adverse events occurred during follow-up. At the latest follow-up in November 2025, the patient remained clinically stable, with no evidence of PTC recurrence or CLL progression, and thyroid function test results showed decreased T3, elevated T4 and free T4, mildly elevated thyroid-stimulating hormone, and free T3 within the reference range. The present case highlights the importance of a comprehensive diagnostic work-up and provides practical guidance for the diagnostic and therapeutic management of patients with dual malignancies.

Thyroid nodules are detected in a large proportion of adults undergoing high-resolution ultrasonography, yet only a minority harbor clinically significant cancer. The clinical problem is therefore not only cancer detection but calibrated risk stratification: avoiding delayed diagnosis of aggressive disease while limiting unnecessary biopsies, molecular testing and diagnostic surgery. Artificial intelligence (AI) has moved rapidly from experimental image classification to clinically-deployed decision support. This invited review synthesizes current evidence for AI applications in the evaluation and management of thyroid nodules and differentiated thyroid cancer, emphasizing ultrasound-based computer-aided diagnosis, indeterminate cytology, molecular integration, cytopathology and histopathology, lymph-node assessment, report quality control, surveillance and emerging multimodal large language models. Commercial and near-commercial systems including S-Detect, AmCAD-UT, Koios DS Thyroid, AIBx and newer deep-learning systems show that AI can improve consistency, support less experienced readers and, in selected settings, reduce low-yield fine-needle aspiration without unacceptable loss of sensitivity. A particularly important future role may be AI-enabled de-escalation, in which image-derived estimates of benignity help support surveillance when clinical, sonographic, cytologic or molecular risk signals are concordantly low. However, performance varies by case mix, cancer prevalence, scanner platform, operator experience, geographic cohort, reference standard and whether the model is used as a stand-alone classifier or second reader. The strongest evidence supports AI as an adjunct to standardized ultrasound risk stratification and shared decision-making, not as a replacement for expert clinical judgment. Future progress will depend on prospective multicenter validation, transparent reporting, local calibration, workflow design, regulation, post-market surveillance and assessment of patient-centered outcomes.