Thyroid Nodules and Cancer — Overdiagnosis Arithmetic, Bethesda with Molecular Rescue, Lobectomy and Surveillance Verdicts, and the Prophylactic Neck Question

A 45-year-old woman with a 2 cm Bethesda V nodule, a 38-year-old man with a 9 mm low-risk papillary microcarcinoma, and a 60-year-old woman with a rapidly enlarging BRAF-mutated neck mass with stridor. One needs lobectomy-versus-total counselling with completion arithmetic, one needs active surveillance by contract with rescue terms, and one needs anaplastic staging with mutation-matched therapy before any knife. The examiner will watch you open with overdiagnosis, correct Bethesda for NIFTP, compare ultrasound systems by their trade-offs, quote lobectomy equivalence with complication discounts, omit ablation by IoN numbers, defend the central neck node by node, and re-stratify risk after treatment — with every number taken from the papers named beside it.^{[2][17][12][22][26][34][48]}

Overview & Definition — nodule, differentiated cancer, medullary, anaplastic

The thyroid nodule is common and mostly benign; differentiated cancer (papillary, follicular) is increasingly prevalent yet usually indolent; medullary arises from C cells with calcitonin and RET; anaplastic kills half of thyroid-cancer deaths despite its rarity — four diseases sharing one gland and almost nothing else.^[6][55][62] The epidemic sentence comes first: US incidence rose 5.0 to 14.6 per 100000 from 1975 to 2009 before plateauing, early-stage detection outpaced late-stage throughout 1981-2011, overdiagnosis explains 5.5 to 60.1% of papillary cancers by age and sex with 82000 excess cases — and across 63 countries three-quarters of 2.3 million cases were overdiagnosed, from zero in Uganda to over 85% of female cases in Korea, Cyprus, China and Türkiye.^[3][1][2] The strategic arc fits one sentence: risk-stratify by ultrasound, categorise by Bethesda with NIFTP correction, rescue indeterminate with molecular testing, resect by risk-adapted extent, omit or minimise ablation by trial numbers, dissect nodes by indication, surveil microcarcinoma by contract, re-stratify by response, time medullary by calcitonin and RET growth, and match anaplastic therapy to mutation.^{[11][14][17][18][22][26][34][40][48][55][62]}

Classification — ultrasound systems, Bethesda, NIFTP, ATA risk

Stratify by ultrasound with the trade-offs stated: across six systems at best thresholds sensitivity runs 64-77% with specificity 82-90%, and the network ranks ACR TI-RADS first followed by K-TIRADS — while head-to-head in 902 nodules the ATA pattern is most sensitive (95.0 vs 80.2% ACR) but least specific (38.1 vs 68.9%), and the unnecessary-biopsy price runs 25.8% ACR, 51.2% ATA and 59.4% Korean — so sensitivity is bought with needles.^[11][12] Grade the single-system anchors: Kwak TI-RADS climbs 0/1.3/4.8/30.3/75.5/95.5% across categories 2 to 5 with 97/90/40/99/91% test performance — and in surgical cohorts KWAK leads efficiency above 1 cm (AUC 0.92) with ACR most specific (79.7%) and ATA most sensitive (95.5%).^[10][13] Categorise by Bethesda with pooled risks: 25445 aspirations with 25% excised give 97% sensitivity but only 50.7% specificity (accuracy 68.8%) with positive value 55.9 and negative 96.3 — while indeterminate carries 27% (AUS/FLUS) and 31% (FN/SFN) malignancy across 145928 specimens, and fine-needle biopsy itself runs 85.6/71.4% with likelihood ratios 3.0/0.2, unchanged over time.^[14][15][16] Correct every Bethesda number for NIFTP: reclassification cuts risk in all categories except I across 14153 nodules — largest absolute fall in V (16 points) and largest relative in III (32%) — with surgical Bethesda V/VI carrying 14% and 3% NIFTP prevalence and a 5.5-point risk difference — so pre-2017 tables overcall, and children match adults on Bethesda outputs across 3687 nodules.^[17][21][66]

Populations & Denominators — the cohorts that frame every decision

The burden cohorts run O'Grady US 1981-2011, Li 63 countries with 97 registries plus 385-registry subtype data, Chen US 91968 cancers with age-period-cohort modelling, Chen-review four decades, and Qian paediatric 1973-2013 with 0.48-to-1.14 incidence.^{[1][2][3][4][5]} The diagnosis cohorts contribute Brito 31 studies with 18288 nodules at 20% cancer, Kwak 3980 prospective nodules, Kim-network 39 studies with 49661 patients, Ha 902 nodules at 29.5% malignant with 7.6% off-pattern, Gao 2544 surgical nodules at 66.1% malignant, Bongiovanni 25445 aspirations, Straccia 51 articles with 145928 specimens, Hsiao pooled biopsy accuracy, Vuong 14 studies with 14153 nodules, Livhits 346 randomised indeterminate nodules at 20% malignant, Borowczyk 1086 plus 459 nodules, Nguyen 132 studies with 66448 nodules (45.6% indeterminate), Bongiovanni-NIFTP 13752 thyroidectomies, and Vuong-paediatric 17 articles with 3687 nodules.^{[9][10][11][12][13][14][15][16][17][18][19][20][21][66]} The extent cohorts contribute Lee 2014 propensity-matched microcarcinomas with 11.8-year median follow-up, Jeon 381 hemithyroidectomies, Wu 6 studies with 1894 lateral-node-positive patients at 76.9 months, Soibelman completion trends before and after 2015, IoN 504 randomised low-risk patients at 33 UK centres, HiLo 438 randomised with 6.5-year median follow-up, Vardarli 4 trials with 1501 patients, and Asif 10 studies with 5260 patients.^{[22][23][24][25][26][27][28][29]} The neck cohorts contribute Zetoune 1264 patients, Wang 11 studies with 2318, Zhao 17 studies with 4437, Chen 23 studies with 18376, Hughes 14 studies, Hartl rethink, Papini 55 advanced N0 patients at 10 years, Ren 1295 ANZTCR patients, Giordano 1087 dissections, and Aspinall UKRETS volume bands.^{[30][31][32][33][34][35][36][37][38][39]} The surveillance cohorts contribute Miyauchi 1235 trial plus 30-year 2429, Leboulleux framing, Kwon 192 Korean patients, Lee-Korea 706 multicentre, Fujishima 2707 with 225 delayed operations, Saito 308 with loss-to-follow-up arithmetic, and Sugitani consensus indications.^{[40][41][42][43][44][45][46][47]} The risk cohorts contribute Tuttle 588 re-stratified patients, Momesso 507 without ablation (187 lobe, 320 total), Park 357 without ablation at 8.6 years, Jeon-modified 715 at 8 years, Kim 9753 multicentre thyroglobulins, Webb 15 studies with 3947, EXAM 330 cabozantinib patients, Machens growth and prophylactic cohorts, Jassal 1454 cancers with 43 medullary, Mao 176 hemithyroidectomies, Spörlein 48 sporadic medullaries, DTP 71 BRAF-anaplastics, atezo 42 trial patients, FAST consensus, Evans 479 advanced anaplastics, Wang 203 mutated anaplastics, and Priantti pooled BRAF/MEK.^{[48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65]}

Clinical Presentation — the incidental nodule, the microcarcinoma, the lethal neck

The differentiated nodule declares through imaging: screen-detected, asymptomatic, often sub-centimetre — the very phenotype driving overdiagnosis with early-stage detection outpacing late-stage for three decades — so the incidentaloma is the commonest presentation and the epidemic sentence precedes the needle.^[1][3] The microcarcinoma declares through surveillance eligibility: 9 mm intrathyroidal without nodes, invasion or alarming location — the Kuma phenotype with 8% enlargement and 3.8% nodal migration at 10 years and zero deaths either arm — so the small cancer is a contract, not a crisis.^[40][47] The medullary declares through calcitonin: 3% of thyroid cancers with a quarter of indeterminate cytologies hiding raised serum levels and suboptimal surgery without dissection — while RET carriers grow millimetres yearly with decade-long imaging windows — so the hormone precedes the operation.^[57][55] The anaplastic declares through speed and stridor: half of thyroid-cancer deaths from a rare tumour with 7.6-month median survival — BRAF-mutated at 24 months against RAS at 2.64-fold death hazard — so the rapidly enlarging neck is staged for systemic therapy first, surgery second.^[62][63][64]

Differential Diagnosis — benign, NIFTP, differentiated, medullary, anaplastic

Split benign from malignant before needling: spongiform or cystic appearance alone avoids biopsy in the threshold model, taller-than-wide carries the highest odds at 11.14 — so the ultrasound pattern decides the needle, not size alone.^[9] Split NIFTP from carcinoma after Bethesda V/VI: 14% and 3% NIFTP prevalence with lobectomy adequate for the entity — so the suspicious-or-malignant aspirate still earns extent restraint where NIFTP is plausible.^[21] Split medullary from follicular-derived before operating: indeterminate cytology hides medullary in over a quarter with raised calcitonin, and operating without the hormone risks suboptimal dissection — so calcitonin precedes surgery where medullary is plausible.^[57] Split anaplastic from operable before cutting: stridor with a rapidly enlarging BRAF-mutated mass earns mutation-matched systemic therapy with 43-month cohort survival — so the lethal neck is biopsied and profiled, never debulked blind.^[61][62]

Name the entity aloud before planning extent — the viva rewards the candidate who separates what NIFTP decides from what invasion and nodes decide.^[17][30]

Clinical & Bedside Assessment — neck, voice, calcium, eyes of the scan

Examine the neck for nodes, fixation, stridor and voice before every plan: clinical nodes, distant spread, cord paralysis from invasion and tracheal protrusion mandate immediate surgery under consensus — while adherence to trachea or cord-course location does the same — so the bedside examination overrules surveillance eligibility.^[47] Assess voice and calcium risk against volume: permanent hypoparathyroidism and palsy fall to 3% and 2.6% only above 100 cases yearly — so the consent quotes the surgeon's denominator beside the disease numerator.^[39] Palpate the operative plan against complications: total thyroidectomy multiplies transient hypocalcemia against lobectomy (8.6 vs 0%, 9.4 vs 1.6% palsy in multifocal microcarcinoma; RR 0.01-0.06 for hypo in lateral-node disease) — so extent is priced in calcium and voice before oncology.^[23][24] Stage the anaplastic airway first: stridor with BRAF mutation earns dabrafenib-trametinib with pembrolizumab (17.0 vs 9.0 months) or neoadjuvant-to-surgery (63.0 months exploratory) — so the airway plan precedes the cancer plan.^[60]

Investigations — ultrasound pattern, Bethesda, molecular, calcitonin, thyroglobulin

Biopsy by pattern with the FNA price stated: ATA sensitivity 95.0% costs 51.2% unnecessary biopsies against ACR at 80.2% with 25.8% — while 7.6% of nodules fit no ATA pattern yet carry 10.1% risk — so the system is chosen with its miss rate and its needle rate together.^[12] Refine indeterminate with molecular testing by randomised numbers: RNA and DNA-RNA tests run 80/85% specific with 53/63% predictive values, avoiding diagnostic surgery in 51/49% — while global pooling shows conventional management more than doubles surgical odds (OR 2.258) but resects fewer malignancies (OR 0.594) — so the test spares operations by selecting them.^[18][20] Measure calcitonin where medullary hides: over a quarter of indeterminate-or-nondiagnostic medullaries show raised serum levels with dissection planned on the result — so the hormone is the investigation that changes the operation.^[57] Read thyroglobulin by context: preablation levels below threshold carry 94.2% negative value across 3947 patients — while without ablation 0.3 ng/mL optimally predicts structural recurrence and 5.0 marks biochemical-incomplete risk — so the marker is read against the ablation decision, never alone.^[53][52] Re-stratify every differentiated cancer at 2 years: excellent response collapses intermediate risk 21 to 2% with 98.3% disease-free survival — while incomplete response multiplies risk 13/41/79% across strata — so follow-up intensity follows response, not presentation.^[48][51]

Management — Extent: lobectomy equivalence with completion arithmetic

Give lobectomy equivalence exactly: propensity-matched microcarcinoma (1015 total vs 999 lobe with central dissection, 11.8-year median) shows no death difference (HR 1.05) and no recurrence difference (HR 3.08, ns) — while unilateral multifocal microcarcinoma after lobe-versus-total shows recurrence 3.15 vs 0.78% (ns) with transient hypocalcemia 0 vs 8.6% and palsy 1.6 vs 9.4% favouring the lobe — so oncology ties and complications decide.^[22][23] Give the lateral-node extension exactly: 6 studies with 1894 unilateral cancers with lateral metastasis at 76.9 months — lobectomy cuts complications (RR 0.21, transient hypo 0.01, permanent hypo 0.06, transient nerve injury 0.49) with 5-year recurrence-free survival tied (HR 1.03) and recurrence tied (RR 1.10) — pending prospective validation, the lobe holds even with N1b.^[24] Give the completion trend exactly: completion ran 51.8% before 2016 against 43.1% after the 2015 guidelines — a 17% early-completion reduction — so de-escalation is measured, not merely preached.^[25]

The extent resolution: lobectomy for low-risk unifocal and selected multifocal and lateral-node disease, total where invasion, nodes beyond, or patient preference demands — with completion consented as the minority path.^{[22][23][24][25]}

Management — Ablation: low-dose equivalence with no-ablation noninferiority

Give HiLo exactly: 438 randomised T1-T3 ablations — 21 recurrences (11 low, 10 high) with 7-year rates 5.9 vs 7.3% (HR 1.10, ns) and no T3/N1 difference — with rhTSH preparation tied to withdrawal (HR 1.62, ns) — so 1.1 GBq replaces 3.7 GBq without recurrence cost.^[27] Give the pooling exactly: 4 trials with 1501 patients find low-dose recurrence no higher (OR 0.93) — and 10 studies with 5260 find the same (OR 0.66, ns) — so the dose question is settled twice over.^[28][29] Give IoN exactly: 504 low-risk patients (251 no-ablation vs 253 ablation) at 6.6-6.8 years — 17 recurrences (8 vs 9) with 5-year recurrence-free 97.9 vs 96.3% and absolute difference 0.5 points establishing noninferiority — with pT3/N1a recurring more (9%/13% vs 3%/2%) yet equally without ablation — so pT1-T2 N0/Nx disease skips ablation with hospitalisation, side-effects and costs avoided.^[26]

The ablation resolution: 1.1 GBq where ablation is chosen, no ablation where IoN criteria fit — with pT3/N1a counselled, not excluded.^[27][26]

Management — Central neck: indication arithmetic with volume discipline

Give the recurrence math exactly: Zetoune 2.02 vs 3.92% (OR 1.05, ns) — Wang RR 0.59 (ns) with 31 treated per recurrence prevented — Zhao RR 0.66 significant — Chen OR 0.65 with transient nerve injury doubled (2.03), transient hypo doubled (2.23) and permanent hypo doubled (2.22) — Hughes occult nodes in half with permanent hypo 3.45 vs 1.55% and palsy tied (0.96 vs 0.89%) with recurrence 4.55 vs 6.75% — so the benefit is small, inconsistent and bought in calcium.^{[30][31][32][33][34]} Give the modern restraint exactly: nodal recurrence strikes under 10% without dissection with no survival advantage shown — a 55-patient 10-year advanced-N0 comparison finds recurrence, disease-free and overall survival all tied — while node-negative dissection halves completion (aRR 0.65) and ablation (aRR 0.55) — so dissection stages and spares therapy without curing more.^[35][36][37] Give the harm gradient exactly: 1087 dissections show palsy tied across extent (3.6/3.9/5.5% transient, 1.0/0.5/2.3% permanent) while transient hypo climbs 27.7 to 36.1 to 51.9% — and registry volume above 100 yearly holds permanent hypo at 3% with palsy 2.6% — so the dissection belongs to high-volume hands or not at all.^[38][39]

The neck resolution: therapeutic dissection for proven nodes, prophylactic by node-by-node justification with calcium consent — never by habit.^[35][33][38]

Management — Surveillance: the Kuma contract with rescue terms

Give the Kuma arithmetic exactly: 1235 patients with 8% enlargement and 3.8% nodal migration at 10 years, zero deaths either arm — against surgery's 4.1 vs 0.6% temporary palsy, 16.7 vs 2.8% temporary hypo and 1.6 vs 0.08% permanent hypo with 2 permanent palsies — so observation wins on harm with rescue surgery curing the progressors.^[40] Give the 30-year confirmation exactly: 3.8% enlarge (4.7/6.6% at 10/20 years) with 0.8% nodal migration (1.0/1.6%) — conversion surgery carries 0.6% recurrence at 10 years against 0.7% for immediate low-risk surgery, with progressor-conversion at 3.3% (ns) — so delayed surgery on progression matches immediate surgery on indolence.^[44][45] Give the Korean replication exactly: single-centre 14% enlarge (volume-only in 23 of 27) with 0.5% nodal migration and 13% delayed surgery at 31.2 months (29% node-positive) — multicentre 9.6% composite progression (5.3/14.2% at 2/5 years) with size criteria at 5.8/5.4% — so volume watches what diameter misses.^[42][43] Give the contract terms exactly: immediate surgery for nodes, distant spread, cord paralysis from invasion, tracheal protrusion, adherence or cord-course location — with 28.6% lost to follow-up at 5 years (HR 1.62 vs surgery) yet zero deaths among the lost — so surveillance is offered with rescue indications named and follow-up enforced.^[47][46] Give the framing exactly: half the incidence rise is microcarcinoma, recurrence runs 1-5% against irreducible 1-3% permanent surgical harm — so surveillance with curative intent suits the properly selected.^[41]

The surveillance resolution: observe the eligible, rescue the progressors, operate the excluded — with loss-to-follow-up quoted beside progression.^[40][44][46]

Management — Response: dynamic risk with and without ablation

Give the re-stratification exactly: initial 3/21/68% across low/intermediate/high collapses to 2/2/14% with excellent response and rises to 13/41/79% with incomplete response — with modified criteria at 98.3% disease-free for excellent against 6.8% for structural-incomplete (RR 16.5/41.3/281.2) — so the 2-year response rewrites the operative risk.^[48][51] Give the no-ablation validation exactly: 507 patients (lobe and total) with excellent response at 0% structural disease, indeterminate at 1.3%, biochemical-incomplete at 31.6% — and 357 patients with 3.6% structural recurrence at 8.6 years, incomplete biochemistry at HR 20.8 and structural at 243.3 — so response works without remnant ablation.^[49][50] Give the thyroglobulin cutoffs exactly: 0.3 ng/mL optimally predicts structural recurrence without ablation (AUC 0.815/0.772/0.816) with 5.0 marking biochemical-incomplete risk — while preablation levels below threshold carry 94.2% negative value — so the marker is read against the ablation just given or withheld.^[52][53]

Management — Medullary: calcitonin timing with RET growth windows

Give the hormone exactly: 3% of thyroid cancers are medullary with over a quarter of indeterminate cytologies hiding raised calcitonin and suboptimal surgery without dissection — so calcitonin precedes surgery where medullary hides.^[57] Give the growth exactly: node-negative ATA-A/C carriers grow 0.4-0.5 mm yearly with small tumours taking over a decade to image — while prophylactic childhood surgery at assay-threshold calcitonin cures near 100% with rare permanent harm — so carriers are timed by hormone in experienced hands.^[55][56] Give the extent exactly: hemithyroidectomy series show 26.0% contralateral foci with 5.1% occult to ultrasound — against a 48-patient sporadic series with zero occult disease where persistent calcitonin above 2 pg/mL predicts recurrence — so total thyroidectomy stays standard with hemithyroidectomy a counselled exception.^[58][59] Give the systemic exactly: cabozantinib doubles progression-free survival (11.2 vs 4.0 months, HR 0.28) with 28% response against zero — for progressive metastatic disease.^[54]

Management — Anaplastic: mutation-matched therapy before the knife

Give the burden exactly: half of thyroid-cancer deaths from a rare tumour with 24% 2-year and 23% 5-year survival at 7.6-month median — improved only where systemic therapy is given — so nihilism is outdated but urgency is not.^[62][63] Give the BRAF pathway exactly: dabrafenib-trametinib with pembrolizumab reaches 17.0 vs 9.0 months (PFS 11.0 vs 4.0) with neoadjuvant-to-surgery at 63.0 months exploratory — atezolizumab triplets reach 19 months overall with 43 months in BRAF cohort — pooled BRAF/MEK response 68.15% with disease control 85.39% and 1-year survival 64.97% — so BRAF-mutated disease is treated systemically first with surgery for responders.^[60][61][65] Give the mutation split exactly: BRAF-mutated at 24-month median against RAS at 2.64-fold death hazard — with FAST consensus demanding molecular profiling to find the BRAF patients — so every anaplastic neck is profiled before it is cut.^[64][62]

Complications & Pitfalls — the six traps

The epidemic-blind trap — needling or operating without stating overdiagnosis, when three-quarters of global cases are overdiagnosed — two-fifths of young women's rising to three-fifths past 50; the epidemic sentence opens every plan.^[2][1]

The pre-NIFTP trap — quoting Bethesda V at face value without the 16-point absolute and 32% relative corrections, then resecting totally for the category alone; reclassify first, then choose extent.^[17][21]

The maximalist trap — defaulting to total thyroidectomy with ablation for low-risk disease, when lobectomy ties oncology with fewer calcium and voice events and IoN proves no-ablation noninferior at 97.9 vs 96.3%; de-escalation is the examined answer.^[22][26]

The routine-central trap — dissecting the prophylactic central neck by habit at 31 treated per recurrence against doubled transient injury; justify node by node with calcium consent in high-volume hands.^[31][33][39]

The casual-surveillance trap — offering observation without the progression contract, when 8% enlarge, 3.8% node-migrate and 28.6% vanish by 5 years; surveillance means rescue terms with enforced follow-up.^[40][46]

The blind-medullary trap — operating indeterminate cytology without calcitonin, when over a quarter hide raised levels and dissection goes suboptimal; measure the hormone where medullary hides and time carriers by assay threshold.^[57][56]

Prognosis & Disposition — the numbers that set expectations

^{[2] [3] [5] [11] [14] [18] [22] [25] [26] [31] [33] [39] [40] [44] [45] [46] [48] [56] [60]}

Special Populations — contexts that change the emphasis

The child inherits restraint: adult therapy harms the low-mortality young, guidelines restrict to 18-and-under evidence, Bethesda outputs match adults across 3687 nodules, yet paediatric incidence climbs steeply since 2006 — so children get adult-grade diagnosis with child-grade therapy.^[8][66][5] The RET carrier inherits timing: millimetric yearly growth with decade-long windows means prophylactic surgery at assay-threshold calcitonin cures near 100% — so the gene-positive child is watched by hormone, operated once, in experienced hands.^[55][56] The elderly low-risk adult inherits surveillance candidacy: Kuma criteria favour the older patient with small intrathyroidal disease — while progression concentrates under 40 — so age supports observation where youth argues surgery.^[40][47] The BRAF-anaplastic patient inherits speed: 17.0-month survival with triplet therapy and 63.0-month exploratory neoadjuvant outcomes replace the 7.6-month natural history — so the stridulous BRAF neck is treated systemically first.^[60][63] The indeterminate-nodule patient inherits molecular rescue: half avoid diagnostic surgery at 20% prevalence with RNA/DNA-RNA specificity 80/85% — so the Bethesda III/IV adult is tested before being scheduled.^[18]

Evidence, Guidelines & Regional Differences — the five stories and who led them

The epidemic story is O'Grady-to-Li: US attribution with 82000 excess cases, 63-country pooling at 75.6% overdiagnosed, American plateau at 14.6 with paediatric climb — and review framing of imaging-driven detection with advanced-stage honesty.^{[1][2][3][5][4]} The diagnosis story is Brito-to-Livhits: ultrasound odds with taller-than-wide leading, TI-RADS validated prospectively, networks ranking ACR first, head-to-head pricing sensitivity against needles, Bethesda pooled with NIFTP correction, and molecular rescue randomised — a complete chain from pattern to decision.^{[9][10][11][12][14][17][18]} The de-escalation story is Lee-to-IoN: lobectomy equivalence propensity-matched and multifocal, lateral-node lobectomy holding, completion falling post-2015, HiLo halving dose with 6.5-year proof, IoN omitting ablation — extent and adjuvant retreating together.^{[22][23][24][25][27][26]} The neck story is Zetoune-to-Hartl: early pooling null, later pooling split, 18376-patient harm doubling, MD Anderson staging arithmetic, modern restraint with therapy-sparing, volume discipline — the most argued dissection in endocrine surgery, settled node by node.^{[30][32][33][34][35][39]} The risk story is Tuttle-to-Tg: response rewriting ATA estimates with and without ablation, thyroglobulin cutoffs disciplined, medullary timed by hormone, anaplastic matched by mutation — follow-up and rare disease personalised by numbers.^{[48][49][52][56][60]} The stated honesty of this set: no guideline PDF bytes were fetched, so ATA claims are the guideline abstracts' own scope-and-methods words and every number belongs to a trial, meta-analysis or cohort abstract — regional practice varies, so name the study beside every protocol claim.^[6][7][8]

Exam Pearls — the one-liners that score

• Epidemic: 75.6% of 2.3M overdiagnosed; US 5.0 to 14.6 plateauing; 5.5/45.5% men, 41.1/60.1% women; 82000 excess; paeds 0.48 to 1.14.^[2][3][1][5]
• Ultrasound: taller-than-wide OR 11.14; spongiform/cystic avoids FNA; Kwak 0-95.5% ladder; network ACR first; ATA 95.0/38.1 vs ACR 80.2/68.9 with FNA price 51.2/25.8%.^{[9][10][11][12]}
• Bethesda: 97/50.7 with PPV 55.9/NPV 96.3; indeterminate 27/31%; FNB 85.6/71.4 stable over time; NIFTP cuts V 16 absolute, III 32 relative.^{[14][15][16][17]}
• Molecular: indeterminate 20%; RNA/DNA-RNA 80/85% specific avoiding 51/49% surgery; global OR 2.258/0.594; NIFTP 14/3% in V/VI.^[18][20][21]
• Extent: no death/recurrence difference matched; multifocal 3.15/0.78 ns with hypo 0/8.6; lateral-node lobe ties (HR 1.03/RR 1.10); completion 51.8 to 43.1%.^{[22][23][24][25]}
• Ablation: HiLo 5.9/7.3 at 7 yr; pools OR 0.93/0.66; IoN 97.9/96.3 with 0.5-point difference; pT3/N1a higher yet equal untreated.^{[27][28][29][26]}
• Central neck: OR 1.05 ns; RR 0.59 ns with NNT 31; RR 0.66 significant; OR 0.65 with hypo doubled; occult nodes in half; under-10% recurrence unrestrained.^{[30][31][32][33][34][35]}
• Neck restraint: 10-yr advanced-N0 tied; node-negative dissection halves completion/ablation; palsy tied, hypo climbs 27.7-51.9; volume over 100 holds 3/2.6.^{[36][37][38][39]}
• Surveillance: 8/3.8 at 10 yr with zero deaths; 30-yr 3.8/0.8; conversion 0.6 vs 0.7; Korea 14/0.5 and 9.6 composite; LTFU 28.6 HR 1.62; operate nodes/invasion/trachea/cord-course.^{[40][44][45][42][43][46][47]}
• Response: 3/21/68 to 2/2/14 excellent and 13/41/79 incomplete; modified 98.3 vs 6.8; no-ablation 0/1.3/31.6 and HR 20.8/243.3; Tg 0.3/5.0 with NPV 94.2.^{[48][51][49][50][52][53]}
• Medullary: 3% of cancers; calcitonin rescues indeterminate; 0.4-0.5 mm/yr with decade windows; prophylaxis cures near 100%; hemi 26.0/5.1 vs zero; cabo 11.2/4.0 HR 0.28.^{[57][55][56][58][59][54]}
• Anaplastic: half of deaths; 24/23% at 2/5 yr; DTP 17.0/9.0 with neoadjuvant 63.0; atezo 19/43; BRAF/MEK 68.15/85.39; BRAF 24 mo vs RAS HR 2.64; profile every neck.^{[62][63][60][61][65][64]}

Trend paediatric exactly: 0.48 to 1.14 per 100,000 person-years (1973-2013) with post-2006 surge at APC 9.56% (PMID 31120475).^[5]

References66ShowHide

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