ODP485 Hyperthyroidism with Concurrent Thyroid Cancer: Causal Relation or Incidental Association?

Abstract

Introduction Thyrotoxicosis caused by Graves’disease (GD),toxic multinodular goiter (TMG) andtoxic adenoma (TA) can be associated with thyroid carcinoma; furthermore, tumors arisen in hyperthyroid tissue show an aggressive behavior (1). Objective To determine the incidence of thyroid carcinoma in thyrotoxic patients who underwent thyroidectomy and to analyzethe relationship between thyroid cancer, hyperthyroidism and outcomes of hyperthyroid versus euthyroid patients. Materials and Methods We retrospectively studied 304 consecutive hyperthyroid patients who underwent total thyroidectomy, presented in our institute between 2016 and 2021. The indications for surgery were GD (n=167, 3 of them were classified as Bethesda V on the basis of fine needle aspiration biopsy cytological examination prior to surgery), TMG (n=117) and TA (n=20). Results The incidence ofthyroid carcinoma in hyperthyroid patients was 18.1% (n=55) and was more common in patients with TMG (19.7%) and GD (18.6%), than in those with TA (5%). According to the post-surgical histological examination 41 patients were diagnosed with papillary thyroid carcinoma (92.7%), 2 patients were diagnosed with follicular thyroid carcinoma (3.6%), 1 patient with undifferentiated thyroid carcinoma (1.8%), and another patient with medullary thyroid carcinoma (1.8%). Papillary thyroid microcarcinoma accounted for 58.2% of all histological types. Lymph node involvement was found in 22% of the patients with GD, in 13% of those with TMG, and in none of those with TA. Distant metastases were found in 2 patients with GD and in other 2 patients with TMG. Compared with a similar group of 120 euthyroid patients who underwent surgery for thyroid cancer during the same time period, the patients with hyperthyroidism have a 3.4 times greater risk for developing lymphovascular metastases compared to euthyroid subjects (23.6% vs 8.3%, p=. 008). Conclusion Our study showed that thyroid cancers in hyperthyroid patients have an aggressive behaviour, with a worse prognosis than euthyroid patients. A carefully evaluation of all patients with hyperthyroidism is needed to exclude the presence of concurrent malignancy. Routine thyroid ultrasonographic (US) scans and US-guided FNAB should be considered for complete evaluation of hyperthyroid patients. Reference: Medas F, Erdas E, Canu GL, Longheu A, Pisano G, Tuveri M, Calò PG. Does hyperthyroidism worsen prognosis of thyroid carcinoma? A retrospective analysis on 2820 consecutive thyroidectomies. J Otolaryngol Head Neck Surg.2018 Jan 22;47(1): 6. Presentation: No date and time listed