Ectopic thyroid with benign and malignant findings: A case series

INTRODUCTION: Ectopia is the most common sporadically occurring thyroid heterotopy. We present three cases of ectopic thyroid tissue with compression of the upper aerodigestive tract. The first case involved ectopic thyroid tissue in the lingual area of a 60-year-old male with dysphagia, swelling at the base of the tongue, and stomatolalia. The second case was a 66-year-old female with papillary thyroid carcinoma (PTC) in a thyroglossal duct cyst. The third patient was a 50-year-old female with aberrant thyroid tissue in the right submandibular region, with a cribriform-morular variant of PTC (CMV-PTC). METHODS: After resecting the heterotopic tissue and verifying the presence of PTC, the second and third cases underwent total thyroidectomy, and the third patient also underwent radioactive iodine ablation (RAI). Postoperative athyreosis was compensated by permanent levothyroxine substitution. RESULTS: The diagnosis of ectopic thyroid tissue is challenging. Clinical examination together with imaging methods play a key role, especially postoperative histological examination along with scintigraphy and single photon emission computed tomography (SPECT). Ultrasonography should be used to exclude normally localized thyroid tissue and to distinguish other tumorous diseases. In the pre-operative examination, ultrasound-guided fine-needle aspiration biopsy (US-FNAB) often results in technically-difficult sampling and non-diagnostic cytology. CONCLUSION: Resection is the most suitable therapy for clinical symptoms of a foreign body in the upper aerodigestive tract and inflammatory complications; total thyroidectomy follows in case of malignant transformation. Thyroid heterotopy is a rare pathological condition, yet it should be taken into consideration during differential diagnosis of tumorous oropharyngeal and neck lesions.