抄録
Downhill varices are usually caused by superior vena cava (SVC) obstruction due to bronchogenic carcinoma or mediastinal tumors. These structures show retrograde blood flow and are located in the proximal esophagus. Varices in the hypopharynx resulting from mediastinal thyroid tumor are extremely rare. A 70-year-old man visited a local hospital with a 35-year history of enlarging thyroid tumor in the right neck. Fine needle aspiration cytology of the tumor revealed benign goiter. Contrast-enhanced computed tomography showed a huge tumor (13×10×5 cm) in the right to left lobe of the thyroid extending into the mediastinum. Further, a well-enhanced mass mimicking hypopharyngeal cancer was identified in the hypopharynx. Endoscopic examination demonstrated varices in the postcricoid region, so we avoided biopsy. The preoperative diagnosis was huge adenomatous goiter and hypopharyngeal varices caused by obstruction of the internal jugular and brachiocephalic vein by the goiter. Total thyroidectomy was performed and hypopharyngeal varices had disappeared by the next day. The histopathological diagnosis of the thyroid tumor was poorly differentiated carcinoma. Mediastinal thyroid tumor rarely causes downhill varices due to SVC obstruction. However, in this case, signs of SVC obstruction were absent and varices were found not in the upper esophagus, but in the hypopharynx. Obstructed venous flow from the thyroid plexus might circulate via superior laryngeal vein and cause varices in the postcricoid region. When a patient with large mediastinal tumor shows a tumor-like lesion in the hypopharynx, considering the possibility of downhill varices is important before conducting immediate biopsies.
