Endocrine Abstracts

Background: Thyroid incidentalomas are reported with increasing incidence in the last decades. The rate of malignancy in these nodules may reach 9% or higher, depending on the patients selection.

Material and methods: A retrospective study was done on 429 patients with nodular goiter (issued from an iodine-replete area), admitted in the Clinic of Endocrinology, Timisoara, Romania, from January 2011 to December 2013.

Results: The prevalence of thyroid incidentaloma was 22.3% (96 cases). The incidentalomas were diagnosed in most cases on thyroid ultrasound (74%), carotid duplex scanning (13.5%), computed tomography (7.3%) and magnetic resonance imaging (5.2%). The rate of malignancy was 2.08% in incidentaloma group (two cases with follicular variant of papillary thyroid carcinoma (FVPTC)). Among the 49 non-incidentalomas operated patients, the rate of malignancy was 26.5% (four papillary thyroid cancers, four FVPTCs, one anaplastic cancer, one follicular cancer, one Hürtle cell carcinoma, one mixed PTC: classic and FVPTC, one malignant non-Hodgkin lymphoma). There were no significant differences regarding: age, gender, number of nodules, thyroid functionality, or ultrasonographical features between incidentalomas and non-incidentalomas. The ‘suspicious’ nodules at ultrasound were evaluated by fine-needle aspiration biopsy (FNAB). FNAB, performed in 22 incidentalomas, showed: three follicular lesions, three indeterminate, four non-diagnostic, the remaining being benign smears. In the non-incidentaloma group, FNAB (performed in 57 cases) showed: 11 follicular lesions, nine indeterminate, five non-diagnostic, two papillary thyroid cancers, the remaining being benign smears. Among the operated cases, thyroid cancer was diagnosed in 25.4% (15/59), representing 3.5% of the total nodules. The rate of malignancy was 33.3% (3/9) in nodules with <10 mm diameter respectively 24% (12/50) in nodules larger than 10 mm.

Conclusion: Thyroid incidentalomas should be assessed as non-incidenalomas (ultrasonography, cytological examination), because of the similar rate of malignancy.