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

BACKGROUND: 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. METHODS: A total of 448 cases of papillary thyroid carcinoma were studied retrospectively. RESULTS: 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%). CONCLUSION: The diagnosis of papillary carcinoma using the preoperative biopsy enables a more precise oncological procedure with greater chance of biological cure.