A Case of Adenomatous Goiter Associated with Complete Situs Inversus

Abstract

We report a case of adenomatous goiter in a patient with complete situs inversus. The patient was a 64-year-old woman who was referred to our department because of an incidentally detected thyroid tumor. Thyroid tumor was suspected on chest CT, which was performed because of detection of an abnormal opacity on a plain chest X-ray performed during the course of a health checkup. Cervical ultrasonography and CT revealed a mass lesion measuring 40 mm in diameter in the right lobe of the thyroid gland. In addition, thoracic and abdominal CT revealed complete situs inversus. However, there were no vascular abnormalities suggestive coexistence of anomaly of the right recurrent laryngeal nerve, such as an aberrant subclavian artery. When performing a right thyroid lobectomy, in accordance with the preoperative estimation of the course of the right recurrent laryngeal nerve, the nerve was observed to run between the trachea and esophagus and beneath the right common carotid artery at the inferior cervical part, as if it were a normal left recurrent laryngeal nerve. The diagnosis of adenomatous goiter was established by histopathology. Since situs inversus is associated with visceral organs in reversed or mirror-image positions, the non-recurrent laryngeal nerve, if any, would also be expected to exist on the reverse side, i.e., on the left side. In cases with situs inversus, it is of particular importance to carry out careful preoperative assessment of the major vessels embryologically related to the recurrent laryngeal nerve prior to thyroid surgery.