ABSTRACT
ABSTRACT Objective: Follicular thyroid carcinoma (FTC) is less frequent but has a worse prognosis than papillary carcinoma. The available evidence on pre-operative characteristics of FTC is controversial. Our objective was to characterize the clinical, ultrasound and histopathological presentation of FTC patients treated Chile. Subjects and methods: Retrospective analysis of 97 patients treated for FTC in 6 large centers in Chile. We analyzed their ultrasonographic features and classified the nodules according to ATA risk of malignancy and TI-RADS score, as well as the cytological findings according to the Bethesda system. We described their clinical and histopathological findings at diagnosis and classified their risk of recurrence and mortality according to ATA 2015 recurrence risk category and the eighth edition of the AJCC/UICC staging system, respectively. Results: Median age was 48 years and 73.2% were females. The median diameter was 38.8 mm; only 9.5% of them were microtumors. According to ATA risk of malignancy, 86% of the nodules were low or intermediate suspicious, while 78% were category 3 or 4A nodules according to the TI-RADS. Regarding the Bethesda system, 65.9% had indeterminate cytology (20.6% category III and 45.3% category IV). At histological examination, most were minimally-invasive and angio-invasive tumors with less than 4 foci (54.7% and 28.4% respectively). More than 90% of FTC were unifocal and there was no lymphovascular or extrathyroidal invasion or lymph node involvement. Four patients (4.1%) had distant metastases at diagnosis. Most patients (95%) had stage I or II disease according to the AJCC/UICC staging system, while the risk of recurrence was low at 51.5% when using the ATA risk of recurrence scale. Conclusions: At diagnosis, most FTCs were nodules of low or intermediate suspicion at ultrasound, nearly two thirds had indeterminate cytology according to the Bethesda system, and nearly 50% of them were of low risk of recurrence.
ABSTRACT
The thyroid nodule is a frequent cause of primary care consultation. The prevalence of a palpable thyroid nodule is approximately 4-7%, increasing up to 67% by the incidental detection of nodules on ultrasound. The vast majority are benign and asymptomatic, staying stable over time. The clinical importance of studying a thyroid nodule is to exclude thyroid cancer, which occurs in 5 to 10% of the nodules. The Board of SOCHED (Chilean Society of Endocrinology and Diabetes) asked the Thyroid Study Group to develop a consensus regarding the diagnostic management of the thyroid nodule in Chile, aimed at non-specialist physicians and adapted to the national reality. To this end, a multidisciplinary group of 31 experts was established among university academics, active researchers with publications on the subject and prominent members of scientific societies of endocrinology, head and neck surgery, pathology and radiology. A total of 14 questions were developed with key aspects for the diagnosis and subsequent referral of patients with thyroid nodules, which were addressed by the participants. In those areas where the evidence was insufficient or the national reality had to be considered, the consensus opinion of the experts was used through the Delphi methodology. The consensus was approved by the SOCHED board for publication.