The Pharyngolaryngeal Venous Plexus: A Potential Pitfall in Surveillance Imaging of the Neck

P.M. Bunch, R.T. Hughes, E.P. White, J.R. Sachs, B.A. Frizzell, C.M. Lack

Among patients undergoing serial neck CTs, we have observed variability in the appearance of the pharyngolaryngeal venous plexus, which comprises the postcricoid and posterior pharyngeal venous plexuses. We hypothesize changes in plexus appearance from therapeutic neck irradiation. The purposes of this study are to describe the CT appearance of the pharyngolaryngeal venous plexus among 2 groups undergoing serial neck CTs-patients with radiation therapy-treated laryngeal cancer and patients with medically treated lymphoma-and to assess for changes in plexus appearance attributable to radiation therapy. For this retrospective study of 98 patients (49 in each group), 448 contrast-enhanced neck CTs (222 laryngeal cancer; 226 lymphoma) were assessed. When visible, the plexus anteroposterior diameter was measured, and morphology was categorized. At least 1 plexus component was identified in 36/49 patients with laryngeal cancer and 37/49 patients with lymphoma. There were no statistically significant differences in plexus visibility between the 2 groups. Median anteroposterior diameter was 2.1 mm for the postcricoid venous plexus and 1.6 mm for the posterior pharyngeal venous plexus. The most common morphology was "bilobed" for the postcricoid venous plexus and "linear" for the posterior pharyngeal venous plexus. The pharyngolaryngeal venous plexus and its components were commonly identifiable only on follow-up imaging. Head and neck radiologists should be familiar with the typical location and variable appearance of the pharyngolaryngeal plexus components so as not to mistake them for neoplasm. Observed variability in plexus appearance is not attributable to radiation therapy.