Thyroid & Adrenal
All of the following tumours of the larynx involve cervical lymph nodes except
a. Lymphatic drainage of the larynx is distinct for each subsite and is determined by the presence of the fibroelastic membranes as well as the organ's embryogenesis.
b. Two major groups of laryngeal lymphatic channels exist: those that drain areas superior to the fundus of the ventricle, and those that drain areas inferior to it.
c. Supraglottic drainage routes pierce the thyrohyoid membrane with the superior laryngeal artery, vein, and nerve, and drain mainly to the subdigastric and superior jugular nodes.
d. Those from the glottic and subglottic areas exit via the cricothyroid ligament and end in the prelaryngeal node (the Delphian node), the paratracheal nodes, and the deep cervical nodes along the inferior thyroid artery.
e. Small glottic cancers rarely produce cervical metastases (1 to 4%). However, there is a high incidence of lymphatic spread from supraglottic (30 to 50%) and subglottic cancers (40%).
f. When considering treatment for laryngeal tumors, it is useful to categorize them as a continuum from early tumors (those with a small area of involvement or causing minimal or no functional impairment) to advanced tumors (those with significant airway compromise and local extension).
g. For example, severe dysplasia and carcinoma in situ often can be treated successfully with laser ablation or conservative surgical procedures.
h. In contrast, more advanced tumors may require substantial partial laryngeal resection or even total laryngectomy .
i. Further complicating the treatment paradigm is the role of radiotherapy with or without chemotherapy for laryngeal preservation.