Purpose: To assess the incidence and patterns of cervical lymph node metastases in laryngeal and hypopharyngeal carcinomas according to the location, extension, and relation of the primary tumor to the parapharyngeal compartments and tissues arising from different embryological structures as branchial arches and somites.
Patients and methods: The findings of clinical and CT examinations of 230 patients with histological evidence of laryngeal and hypopharyngeal carcinoma (44 T1-, 33 T2-, 41 T3-, 112 T4-carcinomas with lymph node involvement in 116 cases) were evaluated retrospectively. Local tumor spread and relation of the primary to the parapharyngeal compartments and to tissues arising from different embryological structures such as branchial arches and somites were analysed and related to cervical lymph node involvement.
Results: The pattern of cervical lymph node involvement depends upon location and extension of the primary tumor in the adjacent tissues of the larynx and hypopharynx. The density of the lymphatic vessels in these areas determines the likelihood of lymph node involvement. The frequency of NO cases in carcinomas strictly located in the vocal cord (n = 31) was 100%; in the glottic-supraglottic, supraglottic, and transglottic cancer (n = 106) 85%; in larynx-hypopharynx carcinomas (n = 54) 26%; in hypopharynx carcinomas (n = 12) 17%; and in larynx-hypo-oropharynx carcinomas (n = 46) 9%. Tumors in tissues arising from branchial arches 4, 5, and 6 are glottic-supraglottic, transglottic laryngeal, and laryngeal-hypopharyngeal carcinomas. Metastases of these tumors were frequently found in the jugular lymph node chains, particularly if the developed tissue of the "primitive glottis" was invaded by the primary. Upper jugular nodes ipsilateral to a supraglottic or hypopharyngeal primary were usually involved. The frequency of metastases in the jugular lymph node chains decreased in craniocaudal direction. If the tumor invaded the posterior wall of the hypopharynx or tissues.