Extrathyroidal extension is not all equal: Implications of macroscopic versus microscopic extent in papillary thyroid carcinoma

Surgery. 2008 Dec;144(6):942-7; discussion 947-8. doi: 10.1016/j.surg.2008.07.023.


Background: Extrathyroidal extension (ETE) is a risk factor for recurrence of papillary thyroid carcinoma (PTC). Although initial data supporting this was based on gross ETE noted at surgery, current treatment regimens group patients with microscopic ETE-identified only on histopathology-similarly to those with macroscopic (gross) ETE. This study was designed to assess the influence of microscopic ETE on disease recurrence.

Methods: Retrospective analysis of 212 patients undergoing thyroidectomy for PTC between 1995 and 2004 with minimum 3-year follow-up was conducted.

Results: Of 212 patients, 71 had ETE; 32% were macroscopic and 68% microscopic. Patient demographics, tumor variables, and adjuvant therapy were similar between both ETE groups. Recurrence rates were 52% for macroscopic ETE, 21% for microscopic ETE, and 13% without ETE. On multivariate analysis, patients with macroscopic ETE had a 6.4-fold increased relative risk of recurrence compared with patients with microscopic ETE (P < .02; 95% confidence interval, 1.6-25.9) and a significantly decreased disease-free survival (DFS). Furthermore, patients with microscopic ETE had neither a significantly increased risk of recurrence nor different DFS compared with patients without ETE.

Conclusion: Macroscopic ETE has a higher incidence of disease recurrence than microscopic ETE, implying they should be considered separately when devising adjuvant treatment regimens. The significance of microscopic ETE is undetermined.

Publication types

  • Comparative Study

MeSH terms

  • Adenocarcinoma, Follicular / pathology*
  • Adenocarcinoma, Follicular / therapy
  • Adenocarcinoma, Papillary / pathology*
  • Adenocarcinoma, Papillary / therapy
  • Adolescent
  • Adult
  • Aged
  • Female
  • Humans
  • Male
  • Middle Aged
  • Neoplasm Invasiveness
  • Neoplasm Recurrence, Local / pathology*
  • Retrospective Studies
  • Thyroid Neoplasms / pathology*
  • Thyroid Neoplasms / therapy
  • Thyroidectomy
  • Young Adult