Metastatic papillary thyroid carcinoma masquerading as lymphangioma: A rare case report and review of literature.

Papillary thyroid carcinoma coexisting with lymphangioma is a rare presentation of a cystic neck mass. Here, we report a case of papillary thyroid carcinoma masquerading as lymphangioma in the neck clinically and radiologically. Our patient was a 31-year-old man who presented with swelling on the left side of the neck for four months. A detailed history and investigation are summarized, and a review of published literature on similar cases is obtained. The initial computed tomography (CT) scan reported it as lymphangioma, and the fine-needle aspiration cytology (FNAC) reported it as a cystic lesion. However, the excision biopsy showed a picture of metastatic papillary carcinoma of the thyroid with cystic changes and associated lymphangioma. The patient finally underwent total thyroidectomy, which again revealed multifocal papillary thyroid carcinoma with capsular invasion and lymph node metastasis on histopathological examination (HPE). Primary occult carcinoma of the thyroid with metastatic deposits presenting as lymphangioma is a very rare presentation of a cystic neck mass, and very few cases have been reported in the English language literature.