Papillary thyroid carcinoma arising from ectopic thyroid tissue in a neck branchial cyst.

A 35-year-old man presented with a right lateral neck mass for 6 years. Thyroid function test was within normal limits. Computed tomography scan of the neck was suggestive of branchial cyst, tuberculous lymphadenopathy and normal thyroid gland. Fine needle aspiration cytology of cervical lymph node was suggestive of metastatic carcinoma. Branchial cystectomy spearing the thyroid gland was undertaken. Histopathology analysis of the resected specimen confirmed it to be papillary thyroid carcinoma originating from ectopic thyroid tissue in a branchial cyst. The patient was scheduled for total thyroidectomy and neck dissection. Unfortunately, he was lost to follow-up. A brief review of the literature regarding this unusual presentation of thyroid cancer has been provided.