Endocrine Abstracts

Objective: Thyroid malignancy detected incidentally in patients who underwent surgery for thyrotoxicosis has been reported at different rates. The aim of this study was to investigate the rate of incidental thyroid carcinoma (ITC) in thyrotoxic patients underwent surgery in our institution.

Methods: The prevalence of ITC was investigated in patients who underwent surgery for Graves’ disease (GD), toxic adenoma (TA) or toxic multinodular goiter (TMNG) from 2006 to 2008. Fine-needle aspiration biopsy (FNAB) was done for cytological evaluation in all patients with TMNG when we determined a ‘cold’ nodule on scintigraphy, and in those with GD and a concomitant solid nodule. Among patients who had side effects of antithyroid drug therapy, or GD with multiple relapses after therapy withdrawal or responsiveness to antithyroid drugs those who refused radioactive iyode treatment and a goiter causing symptoms of compression underwent surgery.

Results: Among 316 thyrotoxic patients (231 women and 85 men; mean age=48.9 years), 54.1% (n=171) had TMNG, 13.9% (n=44) had TA and 32% (n=101) had GD. Thyroid carcinoma was determined in 27 (8.5%) patients. Fifteen (8.8%) of TMNG, 3 (6.8%) of TA and 9 (8.9%) of GD patients had thyroid carcinoma. The incidence of thyroid carcinoma was similar between subjects with GD, TMNG and TA (P=0.906). Histologic examination revealed 24 papillary (23 microcarcinoma), 2 follicular, and 1 anaplastic carcinoma. Mean diameters of carcinoma was 0.64±0.29 cm (range, 0.10–1.50 cm). While one patient had multifocal tumor tissue (3.7%) 2 patient had vascular invasion (7.4%) and 3 patient had capsular invasion (11.1%).

Conclusion: Our results also suggest that total thyroidectomi was preferable to subtotal to prevent the need for reoperation for patients with thyrotoxicosis after a detailed preoperative evalution for malignancy including FNAB and cervical lymphadenopathy investigation.