Delayed Recurrence of Papillary Thyroid Cancer Presenting as a Solitary Pulmonary Nodule 31 Years After Near-Total Thyroidectomy and Radioiodine Therapy – A Rare Clinical Event

Recurrence of papillary thyroid cancer (PTC) beyond three decades after definitive treatment is a rare clinical event. We report a case of a 69-year-old male with PTC who had undergone near-total thyroidectomy and radioiodine remnant ablation thirty years ago, with an initial low risk of recurrence. He had an excellent response to therapy with negative Iodine-131 (I-131) whole-body scans and undetectable serum thyroglobulin (Tg) levels. In the 31st year of follow-up, chest X-ray and subsequent 18 F-FDG PET/CT, conducted to evaluate vague left-sided chest pain, revealed a solitary pulmonary nodule in the left lung lower lobe. Post video-assisted thoracoscopic surgery (VATS), histopathological analysis of the lung nodule revealed metastatic PTC. This case report emphasises that delayed recurrence of PTC at distant sites, in the absence of locoregional recurrence, must be considered as a possibility in the appropriate clinical scenario, irrespective of the initial risk of recurrence and subsequent response to therapy. It also highlights the critical role of long-term follow-up in patients with PTC.