Endocrine Abstracts

Introduction: Ultrasound examination is the preferred imaging technique for thyroid morphology assessment. Sometimes neck sonography reveals extra-thyroidal pathological formations which may be a cause for diagnostic predicaments. The Zenker diverticulum is a type of esophageal diverticulum, located in a natural area of weakness on the posterior pharyngeal wall. It appears as a structure in close proximity to the left thyroid lobe and can be in some cases misinterpreted as a thyroid, parathyroid or a lymph nodule.

Case report 1: A 42-year old female complaining of cough and dysphagia was referred for a fine-needle aspiration biopsy due to a suspicious finding in the left thyroid lobe. A rounded isoechoic formation with micro-echogenic foci, smooth margins and a thin hypoechoic rim was visualized on the posterior surface of the left thyroid lobe. The finding was suspicious of an esophageal diverticulum. The patient had undergone gastroscopy 3 years earlier and diagnosed with chronic gastritis. The cytological result verified lack of malignancy. Based on ultrasound and clinical suspicion the patient was referred for another endoscopy where a Zenker diverticulum was confirmed.

Case report 2: A 47-year old woman was referred for clinical assessment regarding a lump in the left neck area and dysphagia. She had no comorbidities. During the ultrasound examination a large mass behind the left thyroid lobe and partially behind the right one was visualized. The formation resembled an esophageal enlargement. She was referred to a gastroenterologist and further diagnosed with achalasia.

Discussion and conclusion: The Zenker diverticulum, being in close proximity to the thyroid gland, can in some cases be a cause for misinterpretation. The sonographic appearance of these formations can mimic thyroid nodules. Despite this fact, there are several characteristics, which can be helpful for distinguishing an esophageal diverticulum from thyroid nodules. The typical localization on the posterior surface of the left lobe, the thin hypoechoic rim and the dynamics of the formation when the patient is asked to swallow suggest an esophageal diverticulum, especially when these features are combined. Although not the modality of choice, the ultrasound examination can be of significant importance in discovering esophageal diverticula in the neck area.