Extrathyroid spread in papillary carcinoma of the thyroid: clinicopathological and prognostic study.

Introduction: The extrathyroid spread (ETS) is one of the risk factors that influence mortality and recurrence in patients with papillary carcinoma of the thyroid (PCT). The aim of this study is to analyze the clinical and histologic features and follow-up of a series of patients with ETS undergoing surgery for PCT and to identify patients with a greater risk of presenting with ETS.

Material And Methods: Retrospective study of a series of 200 patients undergoing surgery for PCT, of whom 47 (23.5%) presented with ETS. The clinical and histologic features and follow-up of the patients with ETS were compared with those without ETS using the Pearson chi(2) test. We used a logistics regression model to perform a multivariant analysis for ETS. The survival and disease-free interval rates were calculated using the Kaplan-Meier method.

Results: ETS is most associated with patients over 50 years of age, with tumors over 4 cm that are not encapsulated, with lymph node metastasis, and with certain PCT histologic subtypes after the multivariant analysis. The overall rate of recurrence and mortality in patients with ETS was much higher than in patients without ETS.

Conclusions: PCT patients with ETS have a greater risk of tumor-related recurrence and mortality than patients without ETS. There are patients with certain clinical and histologic features who have a greater risk of presenting with ETS.