OBJECTIVETo evaluate the prognostic impact of tumor size, ultrasonography, central neck lymph node involvement, and age of patients in papillary thyroid microcarcinoma (PTMC).

METHODSTwo hundred and fifty-four patients who underwent total thyroidectomy and central neck dissection for PTMC between 2012 and 2014 were included in this retrospective study. Statistical correlation between tumor size and various clinicopathological parameters was assessed by univariate and multivariate analyses. The ultrasound findings were also evaluated.

RESULTSA total of 254 patients (199 females and 55 males) were included in this study. PTMC showed a predilection for female patients, 41-50 years of age (43.3% of all cases, 110/254), and ultrasound showed hypoechoic nodules. Statistically significant correlation was demonstrated between central neck lymph node involvement and the following factors: age and tumor size. A tumor diameter greater than 0.5 mm (67.3% of all cases) most commonly occurred in patients older than 41 years, and was associated with a higher risk of metastatic central neck lymph node involvement (P<0.05). Hashimoto's thyroiditis was noted in the background in 39.4%(100/254) of cases.

CONCLUSIONSTumor size appears to have a prognostic impact in PTMC, and larger size is more likely to be associated with a higher risk of central neck lymph node involvement. It is controversial whether the etiology of papillary thyroid carcinoma is related to Hashimoto's thyroiditis.