Classification of papillary thyroid microcarcinoma according to size and fine-needle aspiration cytology: Behavior and therapeutic implications.

Abstract

The purpose of this study was to assess and classify cases of papillary microcarcinoma according to size (up to 0.5 cm and between 0.6 and 1.0 cm) and fine-needle aspiration cytology (FNAC). These results were then correlated with clinical and histopathologic factors of worse prognosis. A total of 448 cases of papillary thyroid carcinoma were studied retrospectively. Of the 448 patients, 173 presented with carcinomas of ≤0.5 cm and 275 patients presented with carcinomas sized between 0.6 and 1.0 cm (>0.5 cm). Lymph node metastasis was diagnosed in 6% of the carcinoma cases of ≤0.5 cm and in 16% of the cases with tumors of >0.5 cm. A total of 281 cases tested positive for papillary carcinoma by FNAC, and in 113 cases, the carcinoma was diagnosed during the histopathologic examination. A positive FNAC for carcinoma was correlated with a higher incidence of lymph node metastasis (16% vs 5%). The diagnosis of papillary carcinoma using the preoperative biopsy enables a more precise oncological procedure with greater chance of biological cure.