Ectopic thyroid tissue (ETT) is a rare embryological anomaly, with mediastinal involvement comprising 300,000 ng/mL) with normal thyroid function and negative anti-Tg antibodies. Whole body scintigraphy with iodine-131 demonstrated a large area of functional thyroid tissue in the upper thoracic, beyond the neck. The mass was surgically excised via right thoracotomy. Histopathological examination confirmed a benign multinodular colloid goiter arising from ETT. This case emphasizes the importance of including ectopic thyroid in the differential diagnosis of posterior mediastinal masses, especially in patients with prior thyroid surgery. Multimodal evaluation and surgical resection are essential for definitive diagnosis and symptom resolution.
Kalantari et al. (Tue,) studied this question.