Forgotten goiter: Diagnosis and management. A case report and literature review

A mediastinal thyroid mass discovered years after a total thyroidectomy represents an unusual and uncommon clinical situation. Few cases have been reported and controversy exists regarding the etiology of this ectopic thyroid tissue as well as the optimal surgical approach for resection. We herein describe a case of a mediastinal thyroid goiter discovered five years after a total thyroidectomy.

A 54-year-old Hispanic female was diagnosed with a diffuse cervical goiter secondary to Hashimoto's Thyroiditis and subsequently underwent a total thyroidectomy. Five years later the patient had a chest X-ray as part of a preoperative evaluation for an unrelated and elective surgical procedure. Significant tracheal deviation was identified. A computed tomography scan was obtained and demonstrated a well encapsulated mass in the superior mediastinum resulting in tracheal deviation and compression. This "forgotten" goiter was successfully resected utilizing a standard cervical approach and the patient recovered uneventfully.

A thyroid mass within the mediastinum following a total thyroidectomy is a condition often referred to as "forgotten goiter". Prior reported cases are few, and data is limited, with some uncertainty remaining as to the exact origin of this ectopic thyroid tissue. Possible etiologies include an incomplete removal of the thyroid gland during initial cervical thyroidectomy, or perhaps an autonomous intrathoracic goiter (AIG) - a thyroid gland located in the mediastinum, independent and with no parenchymatous or vascular connection with the cervical thyroid gland.

A trans-thoracic or sternal splitting approach is generally not required for resection of a mediastinal goiter and our experience confirms that the case of the "forgotten goiter" can be safely approached through a cervical incision as well.