Histological variants and prognostic factors of papillary thyroid carcinoma at the Colombian Instituto Nacional de Cancerología, 2006-2012.

INTRODUCTION Thyroid cancer is the most common endocrine neoplasia and the papillary subtype is the most frequent; there are histological and clinical factors associated with a higher risk of recurrence and metastasis. OBJECTIVE The aim of this study was to examine the histological, prognostic and clinical characteristics of papillary thyroid carcinomas diagnosed at the National Cancer Institute of Colombia. MATERIALS AND METHODS A retrospective cohort study was carried out on 619 patients with papillary thyroid carcinoma between 2006 and 2012; we analyzed the sociodemographic, histological, prognostic and clinical characteristics. RESULTS 87.7% of cases were women. The presence of two or more variants in the same case was considered a particular variant, which we called combined pattern. Combined pattern was then the most frequent (50.9%), followed by the follicular variant (23.4%) including subtypes encapsulated and unencapsulated, and the classic variant (22.1%). Mean tumor size was 20.8 mm. More than half of the cases had capsular invasion, extrathyroidal invasion and lymph node involvement. When compared with the other variants, the combined pattern carcinomas had a higher risk of invasion of the thyroid capsule, extraganglionar invasion and metastasis. CONCLUSIONS Our results are in many aspects similar to those already reported. However, the presence of the combined pattern implied a higher risk for capsular invasion, nodal involvement, extranodal involvement and metastasis in comparison with those which had just one variant. Further studies are necessary to confirm these results.