Anatomical classification of laryngeal cancer

The larynx is a common site for upper respiratory tract cancer in adults. From the perspective of anatomy, physiology and tumor origin, the larynx is divided into three parts: supraglottic, glottic and subglottic. There are four types of laryngeal cancer: supraglottic, glottic, subglottic and transglottic.

1. Supraglottic area (i.e. supraglottic type)

It includes the false vocal cords, laryngeal ventricle, spoon-shaped cartilage area, epiglottis and spoon-epiglottic folds. The supraglottic area is connected to the pharynx, and the lateral and posterior parts are connected to the hypopharynx. This area is an air passage, but its main function is to act as a barrier and sphincter for the passage. Solid tumors near this area, such as hypopharyngeal cancer, rarely show symptoms in the early stage, so they are generally diagnosed in the late stage. The early symptoms of supraglottic cancer are not obvious, it is easy to spread to the surrounding area, develops rapidly, and has a high rate of cervical lymph node metastasis. Due to these characteristics, tumors in this area generally have a poor prognosis.

2. Glottal area (i.e. glottal type)

It only includes the vocal cords, and the height of the glottis area is 4 to 6 mm. Its basic function is to pronounce. Cancer in the glottis area causes hoarseness earlier, and the disease progresses more slowly, making it easy to detect and diagnose early. The lymphatic tissue in this area is not rich, so lymph node metastasis rarely or late occurs. The prognosis of glottic cancer is relatively good at all stages. When deep muscles are involved, resulting in limited vocal cord activity and involvement of the thyroid cartilage, the treatment effect and prognosis are poor.

3. Subglottic area (i.e. subglottic type)

Refers to the airway between the vocal cords and the first tracheal ring. It is mainly located in the mucosal area within the cricoid cartilage. Subglottic cancer is rare, and is mostly caused by the invasion of glottis or supraglottic cancer downward. The subglottic area mainly functions as an airway, so tumors in this area can cause wheezing and airway obstruction. This area is rich in lymphatic networks, which are mostly drained to the paratracheal and upper mediastinal lymph nodes, making surgical treatment more difficult.

4. Transglottal type

The tumor extensively infiltrates the paraglottic space under the mucosa and extends into the deep tissues, spanning the supraglottic, glottic, and subglottic regions.