Analysis of cervical and retropharyngeal lymph node metastases in the patients with hypopharyngeal carcinoma with computed tomography and magnetic resonance imaging.

Background and Objective: Hypopharyngeal carcinoma has a high risk for early regional lymphatic dissemination. However, reports about regional lymph node metastases, especially retropharyngeal lymph node metastases, are rare. This research explored the spread of hypopharyngeal carcinoma, especially metastases of the retropharyngeal lymph nodes by studying computed tomography (CT) and magnetic resonance imaging (MRI) images.
Methods: The CT/MRI images of 88 patients with pathologically confirmed hypopharyngeal carcinomas that were performed at our hospital between August 2000 and March 2009 were analyzed retrospectively. The interrelations among local stage and lymph nodes in various regions were analyzed by Chi2 test and multivariate logistical regression.
Results: The rate of regional lymph node metastasis for all patients was 73.9%, and the highest rates of positive lymph nodes were at levels IIa (61.4%), IIb (44.3%), and III (37.5%). Metastases to levels I, IV, V, and VI were rare, as were retropharyngeal lymph-node metastases, which were always combined with metastases at levels II and III. Univariate analysis showed that level-IV metastases correlated to metastases at levels Ib and III; retropharyngeal lymph node metastases were correlated to level IIb and bilateral cervical lymph node metastases. Multivariate analysis showed that level-VI metastases correlated to level IV and that retropharyngeal lymph-node metastases correlated to bilateral cervical lymph node metastases.
Conclusions: Regional lymph node metastases in patients with hypopharyngeal carcinoma follow some regulations, and skip metastasis is rare. The highest rates of positive lymph nodes are at levels II and III. Bilateral lymph node metastases may be a risk factor for retropharyngeal lymph node metastases.