Incidental pharyngoesophageal diverticulum mistaken for a thyroid nodule: Report of two cases.

Pharyngeal or Zenker's diverticulum is an infrequent disorder that results from an outpouching of pharyngeal mucosa through a weakened area in the posterior pharyngeal wall. As it may mimic a thyroid nodule on ultrasonography (US), accurate diagnosis is important to ensure appropriate treatment. Fine-needle aspiration (FNA) is recommended for the initial evaluation of thyroid nodules. We report the FNA diagnosis of two cases of Zenker's diverticulum that were suspected to be thyroid nodules on US. Pap stained aspirate smears showed findings characteristic of Zenker's diverticulum: benign squamous cells, bacteria, and vegetable debris and the absence of colloid and/or thyroid epithelial cells. US and CT findings were consistent with the diagnosis.