Endocrine Abstracts

Aim: Thyroid cancer (TC) is the most common endocrine malignancy, presenting a rising incidence during the last decade, due to continuously rising prevalence of incidental thyroid microcarcinomas (mITCs; ≤1 cm) in benign thyroid diseases treated with total thyroidectomy (TT). Solitary thyroid nodule (STN) is a thyroid condition, which remains under debate regarding the extent of thyroidectomy needed (total or near-total thyroidectomy vs unilateral lobectomy). Objective of the current retrospective study was the assessment of the prevalence of mITC in patients with non-toxic STN subjected to TT, within a time period of 13 years.

Patients-methods: In one Surgical Department, with specialty interest in Neck Endocrine Surgery, a total of 124 patients (90 females/34 males; mean age 47.1 years), underwent TT for solitary thyroid nodule, from 2004 to 2016. Type of thyroidectomy is a choice of the surgical team. All patients were referred for surgical treatment from MDs of Internal Medicine or Endocrinology. Patients with positive/suspicious or non-inclusive cytology, or history of TC, were excluded. Pathological report of mITC was recorded and evaluated according to location of nodule and special features of detected TC.

Results: The prevalence of mITC was 32.3% (40/124 patients), while 84 patients were free of malignancy. Specifically, in 72.5% (29/40 patients) a papillary mITC was diagnosed, while the other types of thyroid carcinoma were: 15% (6/40 patients) follicular mITC, 5% (2/40 patients) papillary+follicular mITC, 5% (2/40 patients) medullary mITC and 2.5% (1/40 patients) foci of anaplastic TC. Interestingly, the case of anaplastic mITC referred to recurrent STN in the remnant lobe after previous lobectomy. Regarding the location and type of pathologically detected mITC, in 7.5% (3/40 patients; 2 papillary/1 papillary+follicular TC), there was multifocal carcinoma in both thyroid lobes. Surprisingly, in 22.5% (9/40 patients; 8 papillary/1 follicular TC) the malignancy was contralateral to STN.

Conclusions: Incidental thyroid microcarcinoma was identified in a significant proportion, nearly 1/3, of patients with solitary thyroid nodule, subjected to total thyroidectomy. More than 1/5 of patients featured mITC at the contralateral lobe. Although the small number of study group comprises a limitation, findings can support the choice of total thyroidectomy as a safe procedure in STN, giving the advantage of treating the disease and also diminishing the possibility of non-detected thyroid cancer or disease recurrence and need for neck re-exploration