Thyroid Gland Invasion in T3 and T4 Laryngeal Carcinoma

Background: Total or ipsilateral hemithyroidectomy or isthmectomy are performed along with total laryngectomy in many cases of advanced cancer larynx with subglottic or extralaryngeal spread. The need for performance of thyroidectomy during TL is controversial. Aim of Work: To asess factors favoring thyroid gland invasion (TGI), indications of hemithyroidectomy, and postoperative complications. Patients and Methods: It is a prospective analytical study that included 40 patients who were diagnosed as T3 or T4 laryngeal carcinoma and had total laryngectomy with at least hemithyroidectomy. The incidence of thyroid gland invasion was reported histopathologically in laryngeal carcinoma and correlated with site and stage of the primary tumor vocal cord fixation, subglottic extension, and prior irradiation. Results: Our study included 40 patients; 37 were males. Four male patients cases (10%) had thyroid gland invasion by laryngeal carcinoma, two cases (5%) had colloidal nodules and one case (2.5%) had follicular adenoma. Thyroid cartilage invasion was evident in all 4 cases (100%) with TGI which was of statistical significance (p-value=0.026). Of the 4 cases with TGI three cases (75%) were transglottic carcinomas, and one case (25) was glottic carcinoma. All were T4a staged 100%. All cases (100%) with TGI had unilateral fixed vocal cord, infiltrated anterior comissure, and unilateral subglottic extension 1cm. Postoperative complications occurred in 28 cases (45%). Three cases with TGI (75%) develop complications. Conclusion: Histological thyroid gland invasion by advanced tumors must not be underestimated. We suggest that subglottic and transglottic tumors are more prone to TGI. We found Thyroid cartilage invasion and preoperative CT findings of thyroid gland were statistically correlated with TGI.