Abstract
Papillary thyroid carcinoma is well known for its low malignant potential and good prognosis. The outcome can be fatal in patients with low compliance and delayed treatment. Recent advances in ultrasonographic screening and US guided fine needle aspiration biopsy has facilitated early diagnosis of papillary thyroid carcinomas. This epithelial thyroid tumour accounts for more than 80 % of all thyroid tumours. An occult primary carcinoma of thyroid presenting as lymphangioma has been reported rarely. We present a case of a 40-year-old female patient with huge cystic midline swelling on the right side of the neck mimicking lymphangioma on USG. MRI neck showed a cystic mass causing displacement of the trachea and arising from Rt lobe of thyroid gland. Hemithyroidectomy was carried out and histopathology revealed papillary carcinoma. In patients with neck swellings presenting as huge cystic mass the differential diagnosis of Intra cystic variant of papillary carcinoma thyroid and metastatic thyroid papillary carcinoma must always be considered prior to planning surgery.