Incidental Papillary Thyroid Carcinoma: Clinical and Histopathological Comparison between Graves’ disease and Euthyroid Nodular Goiter

Incidental papillary thyroid carcinoma (IPTC) is commonly to be detected during thyroidectomy in the case of benign thyroid lesions. Two of the common underlying pathologies are the disease known as Graves' disease (GD) and euthyroid nodular goiter (ENG). This purpose study aimed to determine the incidence, histopathology, and clinical outcome of IPTC in patients undergoing thyroidectomy with GD compared to those having ENG. The study based on the approach methodology was a cross-sectional study about 117 patients who had undergone a thyroidectomy, that is, 53 patients with Graves' disease and 64 patients with euthyroid nodular goiter. The groups were compared in terms of clinical, demographic, and histopathological data. Assessed parameters were tumor size, multifocality, extrathyroidal extension (ETE), tumor lymph node metastasis (LNM), histological variants, preoperative TSH level, post-operative complications, and recurrence rates, with a mean follow-up of 12 months between January 2024 and January 2025. In addition, incidental papillary thyroid carcinoma (IPTC) was found in 37.7% of the patients with Graves' disease (20/53) and 25.0% of the patients with ENG (16/64). Multifocality (30.0% vs. 18.8%), ETE (25.0% vs. 12.5%), and LNM (40.0% vs. 18.8%), which were not statistically significant (p-values 0.45, 0.29, and 0.10, respectively), exhibited numerically higher rates in GD-associated IPTC. It suppressed preoperative TSH (below 0.1 mIU/L) in 67.9% of GD patients and in 3.1% of ENG patients. There were similar rates of complications in the postoperative period, such as hypocalcemia and nerve injury. In conclusion, incidental papillary thyroid carcinoma (IPTC) is more common in Graves' disease patients than in patients with euthyroid nodular goiter. Even though GD-associated IPTC is more trended towards more aggressive histopathological features, nevertheless, both groups had shown very good disease-free survival and similar results of surgery. In addition, the results indicate that although GD could be linked to increased frequency of IPTC, clinical handling of IPTC and prognosis in GD and ENG patients are positive and comparable.