Introduction: A 46-year-old female with a past medical history of Graves’ disease refractory to medical management, thus requiring total thyroidectomy presented to clinic for recurrence of her hyperthyroidism and an increasing midline neck mass two years after her index operation.
Case Description: CT imaging of the neck mass revealed a locally extensive enhancing abnormality immediately anterior to the hyoid bone within the infrahyoid muscles measuring 1.4x.1.9x4.0 cm. This was consistent with an exceedingly rare proliferation of a thyroglossal duct remnant secondary to recurrence of the patient’s Graves’ disease. The patient was treated with surgical resection of the neck mass shown to be ectopic Graves’ activated thyroid tissue by pathology. The patient was restarted on thyroid hormone replacement therapy and has remained euthyroid to date following surgical resection.
Conclusion: The incidence of this event is estimated to be approximately one per a million persons and thus is a rare occurrence in endocrinology. This case highlights the potential shortcomings of surgical management of Graves’ disease. Following surgical resection, the autoimmune status of the patient remains unchanged. Ectopic thyroid tissue can be found anywhere along the embryologic descent of the thyroid gland and as low as the mediastinum. Thus, patients treated with total thyroidectomy should still be monitored regularly for recurrence of Graves’ disease secondary to ectopic thyroid tissue.
Treatment of Ectopic Thyroid Carcinomas in Cranial Mediastinum by Surgical Resection in 3 Dogs
