A hystopathological study of thyroarytenoid muscle invasion in early (T1) glottic carcinoma

Surgical specimens belonging to 16 patients who underwent partial laryngectomy for T1 glottic cancer were subjected to detailed histopathologic examination; 11 of the patients were staged as T1a while 5 were staged as T1b. It was detected that in 11 patients the tumor was confined to the mucosal or submucosal connective layer, and in 5 (31.2%) cases, the tumor invaded the thyroarytenoid (TA) muscle. In cases involving the one-third anterior part of the vocal cords and the anterior commissure, a 50% (4/8) TA muscle invasion was detected. Our finding TA muscle invasion at the rate of 31.2% in our 16 case series clinically staged as T1 revealed that deep invasion did not always impair the vocal cord mobility. Observing TA muscle invasion at the rate of 50% in cases involving the one-third anterior part of the vocal cord and the anterior commissure suggested that TA muscle invasion in the anterior part did not significantly impair mobility.