Factors Determining the Need for Thyroidectomy During Laryngectomy for Squamous Cell Carcinoma

Abstract

Figure 1. CT images. (A) Subglottic extension and (B) thyroid cartilage invasion by SCCA larynx. Objective: To evaluate predictors for thyroid gland invasion in patients undergoing laryngectomy for SCCA of the larynx. Study Design: Retrospective chart review of a single tertiary care hospital. Methods: One-hundred forty-one charts were reviewed. Ninety patients underwent total laryngectomy for laryngeal SCCA between January 1993 and February 2009. Subjects were assessed based on tumor stage, preoperative evaluation (direct laryngoscopy and CT scan), and pathologic analysis. Outcomes included factors suggesting need for thyroidectomy. Results: Thyroidectomy was performed in 36/90 (40%) of patients and thyroid gland invasion by SCCA occurred in 7/36 (19%) cases undergoing thyroidectomy. In those specimens with thyroid gland invasion, 5/7 (71%) demonstrated both subglottic extension and thyroid cartilage invasion. Direct laryngoscopy had high specificity in identifying subglottic extension (p < 0.0001, 100% specificity), but poor sensitivity (60%). Computed tomography proved to be highly sensitive (100% sensitivity) in predicting subglottic extension (p = 0.01), thyroid cartilage invasion, and thyroid gland invasion, but was limited by its specificity (34%, 41%, and 36% respectively). Conclusions: Routine thyroidectomy in conjunction with laryngeal SCCA is unnecessary. Findings of both subglottic extension and thyroid cartilage invasion correlate positively with thyroid gland invasion, and suggest the need for thyroidectomy. However, preoperative prediction of these findings can be difficult. Abstract