Thyroid Tubercle of Zuckerkandl Is More Consistently Present and Larger on the Right: A Prospective Series

Abstract

Objective: The tubercle of Zuckerkandl (TZ) is a lateral projection from the thyroid lobe in the vicinity of the extralaryngeal termination of the recurrent laryngeal nerve (RLN), which is a very useful landmark for identification of the RLN during thyroidectomy. The purpose of the present study was to test our hypothesis that the TZ is more consistently found and is larger on the right than on the left side, and to investigate the frequency of anatomic variations of the TZ. Study Design: Prospective cohort study of 156 consecutive patients undergoing primary total thyroidectomy at an academic teaching hospital. Thyroidectomy was performed using a capsular dissection technique, with identification of the RLN only at its entry point into the larynx, using the TZ as a landmark. In vivo recording of size of right and left TZ was performed. The size of the right and left TZ was compared. Results: Identification of the TZ was 72.6% right side and 53.9% left side (p = 0.003). The mean size of the TZ, when present, was 11.2 mm on the right and 7.5 mm on the left (p = 0.0002). In matched-pair analysis, the right TZ was significantly larger than the left TZ (p < 1 × 10^-7). The TZ overlay the RLN in nearly all cases; however, there were 2 cases (0.8%) of a TZ extending medial to the RLN. In 12 cases (4.7%), the TZ appeared as a bilobed structure. Conclusion: The right TZ is consistently larger and more often identified than the left.