Cytology of thyroglossal cyst papillary carcinoma.

The cytologic and histologic features of two cases of carcinoma arising in thyroglossal cyst are reported. The carcinoma in both cases was papillary thyroid carcinoma. The aspirated cyst fluid in one case revealed only macrophages and benign squamous epithelial cells, while in the other case the cyst fluid showed cytologic features of papillary carcinoma including psammoma bodies and epithelial cells with papillary clustering, intranuclear cytoplasmic inclusions, and positive immunohistochemical reaction to thyroglobulin.