Sir, The 2025 American Thyroid Association (ATA) guidelines for differentiated thyroid cancer (DTC) endorse a risk-adapted strategy that appropriately prioritizes de-escalation in patients with small, intrathyroidal, low-risk papillary thyroid carcinoma (PTC).1 Serial thyroglobulin (Tg), anti-Tg antibodies (TgAb), and high-resolution cervical ultrasound are recommended as the primary surveillance tools, while routine radioactive iodine (RAI) use is discouraged in this group. This paradigm represents a major advance in avoiding overtreatment. However, isolated clinical experience suggests that exclusive reliance on biochemical and structural surveillance may occasionally underestimate true disease burden. A 32-year-old woman presented with a small, slowly enlarging right-sided thyroid swelling of 1 year’s duration. She was clinically euthyroid and had a family history of Hashimoto’s thyroiditis. Neck ultrasonography demonstrated a 1.6 cm × 1.2 cm thyroid imaging, reporting and data system 4 nodules,2 and fine-needle aspiration cytology reported Bethesda Category V, suspicious for PTC.3 She underwent total thyroidectomy. Histopathological examination revealed a unifocal classic variant papillary carcinoma measuring 1.0 cm × 1.0 cm × 0.8 cm, confined within the thyroid parenchyma, without lymphovascular or extrathyroidal invasion. Surgical margins and two sampled lymph nodes were negative (pT1aN0, AJCC 8th edition).4 The background thyroid showed lymphocytic thyroiditis. Based on the ATA 2025 risk stratification, she fulfilled the criteria for low-risk disease. Postoperatively, her serum thyroid-stimulating hormone (TSH) was >50 IU/mL, stimulated Tg was 0.3 ng/mL (<1 ng/mL), and TgAb were elevated at 270 IU/mL (<115 IU/mL). Interpretation of Tg in the presence of TgAb warrants caution. Anti-TgAb can interfere with immunometric Tg assays by masking Tg epitopes or forming immune complexes, resulting in falsely low or undetectable Tg levels despite persistent thyroid tissue or metastatic disease. Consequently, TgAb positivity may obscure biochemical evidence of residual disease and reduce the sensitivity of Tg-based surveillance, particularly in the early postoperative period.” In accordance with the ATA 2025 recommendation R32, such a patient would typically be followed with serial Tg/TgAb measurements and cervical ultrasound, with TSH suppression adjusted to biochemical response. However, in this case, the surgeon, guided by customary postoperative practice, requested a diagnostic I-131 scan. Unexpectedly, the scan demonstrated residual uptake in the thyroid bed and a discrete focus of increased tracer accumulation in the central compartment (Level VI) cervical region, consistent with occult nodal metastasis Figure 1. Therapeutic RAI (100 mCi) was subsequently administered.Figure 1: Postthyroidectomy diagnostic I-131 scintigraphy showing anterior neck and whole-body anterior and posterior views. Residual radioiodine uptake is seen in the thyroid bed along with a focal area of increased tracer accumulation in a central (Level VI) cervical lymph node, consistent with nodal metastasis from differentiated thyroid carcinomaHad the ATA guideline been followed strictly, without a diagnostic scan or RAI, this nodal metastasis might have remained undetected and untreated for a longer period. This observation highlights a potential limitation of de-escalation strategies: Pathological “low-risk” designation does not invariably equate to minimal residual or metastatic disease. In particular, occult central compartment nodal metastases (which are not uncommon in PTC, with reported rates ranging from approximately 20%–40% even in clinically node-negative patients) can be iodine-avid yet clinically silent and not reliably detected by early postoperative ultrasound or Tg-based surveillance, especially in the presence of elevated TgAb. While the ATA 2025 guidelines appropriately seek to minimize unnecessary use of RAI and unnecessary imaging, this case illustrates that omitting functional imaging may allow clinically meaningful disease to go undetected. Single-case reports inherently cannot define incidence or alter standard practice, but they may identify scenarios requiring careful clinical judgment. However, these findings raise an important unresolved question: Whether routine postthyroidectomy diagnostic radioiodine scanning should continue to have a defined role in the early staging of patients currently classified as “low risk.” The ATA 2025 guidelines increasingly incorporate molecular risk stratification, including markers such as B-Raf proto-oncogene, serine/threonine kinase (BRAF), and other genomic alterations, to refine risk assessment. However, access to molecular testing remains limited in many centers, especially in resource-constrained settings, which may further complicate postoperative risk estimation and surveillance strategies. Rather than challenging guideline principles, this report underscores the need for further prospective evaluation to define the balance between diagnostic completeness and therapeutic de-escalation in contemporary DTC management. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Author contribution AB conceptualized the manuscript and managed the clinical case. AB and MNR performed literature review, drafted the manuscript, and approved the final version. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.
Bhattacharya et al. (Mon,) studied this question.