Lymphatic metastasis of laryngeal cancer

Laryngeal cancer is mostly seen in elderly men. Hoarseness and blood in sputum are common symptoms of laryngeal cancer. However, other related symptoms may also appear when laryngeal cancer metastasizes. There are four main ways for laryngeal cancer to spread and metastasize:

1. Hematogenous metastasis

Hematogenous metastasis of laryngeal cancer is not common and usually occurs in the late stage, which is a manifestation of widespread metastasis throughout the body. Only a few patients in the early stage will metastasize to other parts of the body, internal organs or bones through the blood circulation. Among all laryngeal cancer patients, less than 5% have blood metastasis.

2. Implant transfer

The larynx is located at the upper end of the respiratory system. Due to gravity and respiration, the shed cells of laryngeal cancer can fall into the bronchi or lungs along with local secretions and cause implantation metastasis.

3. Direct diffusion

Because the larynx is protected by the thyroid cartilage, it spreads outwards relatively slowly. Its direct spread is first to infiltrate the submucosal membrane along the mucosal surface. Vocal cord cancer mainly spreads backward, forward through the anterior commissure to the opposite vocal cord, and backward to the arytenoid cartilage, but it is rare to invade the ventricular band upward. Supraglottic cancer develops faster and is most likely to spread to the pre-epiglottic space, or invade the pyriform sinus along the epiglottic folds, and can also develop along the pharyngeal epiglottic folds to the epiglottic valley of the posterior pharyngeal wall and the root of the tongue. Subglottic cancer often develops forward and downward, infiltrating the opposite subglottis, but rarely invading backward.

4. Lymphatic metastasis

Laryngeal cancer can metastasize through the lymphatic system, with the cervical lymph nodes appearing first. In the glottic type, metastasis occurs later because there are few lymphatic vessels in the vocal cords. In the supraglottic type, lymphatic metastasis occurs earlier because there is abundant lymphatic tissue.