Abstract

Branchial cysts are the commonest cyst on the lateral aspect of neck and they are mostly benign. However, the sinister papillary thyroid carcinoma may harbor indolently in a branchial cyst. We present a 37 years old lady with painless left neck mass for 3 years. CT scan showed a 0.4 cm hypodense nodule at the upper segment of left thyroid lobe. FNAC showed features of papillary thyroid carcinoma (Bethesda V). She had total thyroidectomy followed by radioactive iodine therapy. Repeat scan did not show any residual disease. We highlight the importance of biopsy on all branchial cysts along with its concurrent thyroid nodule of any size to differentiate between benign and malignant disease.

Key words: Branchial cyst, papillary thyroid carcinoma, ectopic, metastasis