Presentation and Outcomes of Papillary Thyroid Microcarcinomas

Abstract

Despite the increased incidence of papillary thyroid microcarcinoma (PTMC), clinical importance is still controversial. Although risk factors for PTMCs have been identified previously, prognostic factors have not been established clearly. In this study, we aimed to review the presentation features and outcomes of the patients with PTMC. Our study included 144 patients that underwent thyroidectomy and were diagnosed with PTMC according to the postoperative pathology report. All data included age, gender, mode of diagnosis, preoperative ultrasonography and fine needle aspiration cytology (FNAC) results, tumor features (diameter, unilobar localization, multifocality, and stage), the presence of residual thyroid tissue, postoperative serum thyroglobulin (Tg) levels, and radioactive iodine (RAI) ablation were retrospectively reviewed. Only 29 patients (20%) with PTMC could be diagnosed preoperatively with FNAC which was performed in 67% of the patients. The diameter and the number of thyroid nodules were significantly related to the mode of diagnosis. The average size of the tumor diameter was 5 mm ± 2.87. An extrathyroidal extension (ETE) was observed in 10 patients (7%). Lymph node metastasis (LNM) was diagnosed in 6 patients (16%). There was a significant correlation between ETE and tumor diameter with LNM (p = 0.008 and p < 0.001, respectively). Residual tissue was noted in 110 patients (76%). The presence of residual thyroid tissue was significantly related to the extent of surgery, unilobar location, and multifocality. Mode of diagnosis (incidental or non-incidental), tumor diameter, the number of thyroid nodules, unilobar location, and multifocality seem to be related to unfavorable outcomes of patients with PTMC.