Subcentimetric Papillary Thyroid Carcinoma: Does the Diagnosis Kind Impact Prognosis?

Subcentimetric papillary thyroid carcinoma (SPTC) (papillary thyroid carcinoma with less than 10 mm in size) usually presents an excellent prognosis, with few aggressive reported cases. Given the globally increased incidence of SPTC, physicians are struggling with the need to identify prognostic factors to stratify SPTC. The aim was to compare clinicopathological variables and prognosis between clinically and incidentally diagnosed SPTC. Materials and methodsː This is a retrospective observational study on patients with SPTC who underwent thyroidectomy between 2002 and 2015. Two groups were considered: G1 (n=60 (61.9%)), clinical diagnosis (Bethesda III-VI cytology in the thyroid tumor/in cervical lymphadenopathies) and G2 (n=37 (38.1%)), incidental diagnosis (thyroidectomy for benign thyroid pathology). The histological material was reviewed, and molecular analysis of the BRAF, RAS, and TERT promoter (TERTp) genes was performed. Resultsː Ninety-seven individuals were included, 60 (61.9%) of which were from G1, with a predominance of female sex (n=83 (85.6%)). Individuals of G1 were younger (53.0±14.2 versus 59.3±13.9 years; p=0.035), were more frequently treated with 131-iodine (39.2% versus 13.4%; p=0.007), had the largest diameter (8 (p25-p75: 7-9) versus 5 (p25-p75: 4-6.5) mm; p<0.001), and higher frequency of minimal extracapsular invasion (45% versus 24.3%; p=0.041). Increased tumor size was the only independent predictor of a clinical diagnosis (p<0.001). Conclusionsː Clinically and incidentally diagnosed SPTC showed excellent medium- to long-term prognosis. A larger SPTC was more likely a driver of clinical detection than a marker of tumor aggressiveness, but caution should be taken as contradictory data persists.