Cytological Clues to Pharyngoesophageal Diverticula Mimicking Thyroid Nodules.

Pharyngoesophageal diverticula (PED) are uncommon hypopharyngeal outpouchings that may mimic thyroid nodules because of their close anatomic proximity to the thyroid gland. We describe two cases in which PED presented as thyroid nodules and resulted in atypical cytological findings. The first case was a 56-year-old man, who presented with hoarseness and chronic cough. Ultrasonography showed a heterogeneous hypoechoic nodule, and fine-needle aspiration (FNA) revealed benign squamous cells, food debris, inflammatory cells, and microorganisms, supporting the diagnosis of a PED. The second case was a 61-year-old man with chronic throat discomfort and an incidental neck mass initially suspected to be a benign thyroid nodule. Repeated FNA cytology consistently demonstrated benign squamous cells without thyroid follicular cells or colloid, and imaging correlation suggested a PED. These cases highlight the importance of correlating cytological and imaging findings when assessing presumed thyroid nodules to prevent misdiagnosis and unnecessary thyroid surgeries.