In 32 of the 39 specimens, the invasion outstripped PGS, involving elastic cone in 26(81.3%), thyroid cartilage in 24(75.0%) and cricothyroid membrane in 20(62.5%).

• 超出声门旁间隙的病例累及周围组织的频度为：弹力圆锥81.；3%25(26/32)，甲状软骨75