Papillary cystic metastasis versus ectopic thyroid carcinoma in a branchial cyst

Most of neck cyst masses correspond to congenital benign injuries, however, in some cases the metastasis of upper aero-digestive tract and thyroid-gland tumours can simulate these. Given the anatomopathological result of papillary carcinoma in neck cyst, it is necessary to discern between metastasis and primary cancer in aberrant thyroid tissue within a branchial cyst to decide the appropriate treatment. We report two cases of neck cystic metastasis of papillary thyroid carcinoma.