Papillary Carcinoma of Thyroglossal Cyst in a Background of Hashimoto’s Thyroiditis: A Case Report

Abstract

Thyroglossal Duct Cyst (TGDC) is one of the most common congenital neck anomalies that occur due to incomplete involution of the thyroglossal duct. Carcinoma arising in TGDC is rare, accounting for about 1% of cases, with non neoplastic thyroid gland lesions even rarer. This report demonstrates a case of papillary carcinoma with Hashimoto Thyroiditis (HT) of TGDC in the background of HT in the thyroid gland. A 51-year-old woman presented with complaints of midline neck swelling for the past 20 years. Ultrasound revealed an infected thyroglossal cyst. Fine Needle Aspiration Cytology (FNAC) was inconclusive, and the cystic lesion was excised and sent for histopathology. Histopathology showed a thyroglossal cyst with papillary carcinoma along with a focus of HT. The patient underwent total thyroidectomy after a month, which showed features of HT and nodular hyperplasia. There was no evidence of papillary carcinoma in the thyroidectomy specimen. TGDC can harbour malignancies accounting for about 1% of cases. Since TGDC has ectopic thyroid tissue, they should be evaluated for neoplastic and non neoplastic lesions. Also, the evaluation of the thyroid gland is essential for identifying the presence of malignancy to confirm a primary or secondary metastatic carcinoma in a TGDC.