Radiological pitfalls with laryngopharyngeal injectables.

The aim of this report was to describe the computed tomography features of injected carboxymethylcellulose and how it can be mistaken for tumor recurrence. Carboxymethylcellulose is a low-density injectable indicated for short-term vocal fold augmentation. When used in patients with head and neck cancer, differentiating this agent from a neoplastic recurrence can be difficult on imaging. The imaging findings of five patients who received carboxymethylcellulose augmentation are presented to illustrate a potential pitfall of image interpretation. When injectable carboxymethylcellulose is used in cancer patients, knowledge of the injection sites, material used, and procedural history can avoid misinterpretation of monitory imaging.