Clinical and histological characteristics of papillary thyroid microcarcinoma: results of a retrospective study in 243 patients

CONTEXT: The recognition of thyroid microcarcinoma has increased due to the widespread use of ultrasound-guided fine-needle aspiration biopsies. OBJECTIVE: The objective of this study was to describe histological and clinical characteristics of papillary thyroid microcarcinoma (PTMC) less than or equal to 1 cm. DESIGN: This study was a retrospective cohort. SETTING: This study was conducted at a university hospital endocrine clinic. PATIENTS: Over a 9-yr period, 243 consecutive patients with PTMC were studied. RESULTS: PTMC was an incidental finding at surgery in 21.4% of the PTMC cases. There were no differences in the clinical characteristics between those with incidental PTMC and those with suspected thyroid carcinoma. None of the patients with a cancer less than 8 mm had distant metastases, whereas distant metastases were observed in patients with cancers >/= 8 mm (P </= 0.05). Disease-related mortality was not observed. CONCLUSIONS: PTMC is prevalent in the population. Among patients with PTMC, tumor size more than 8 mm is associated with more aggressive disease.