Abstract
BACKGROUND
Ectopic thyroid gland is a rare developmental anomaly caused by aberrant migration of thyroid tissue during embryogenesis. Misdiagnosis as autoimmune thyroiditis, particularly the atrophic form, may occur due to overlapping clinical features, especially in the hypothyroid state.
CASE PRESENTATION
We report the case of a patient who was treated for autoimmune thyroiditis for more than 20 years. Comprehensive imaging with ultrasound and SPECT/CT ultimately revealed an ectopic sublingual thyroid gland, with no orthotopic thyroid tissue present.
CONCLUSION
This case underscores the importance of thorough imaging evaluation in patients with hypothyroidism and absent thyroid tissue in the normal anatomical location, to avoid prolonged misdiagnosis and inappropriate management.