Hyalinizing trabecular adenoma of the thyroid gland--a report of two cases.

Hyalinizing trabecular adenoma (HTA) is a specific variant of thyroid adenoma with a particular histological pattern. Immunohistochemistry is the best way of differentiating these adenomas. Of special interest is a strong positive cytoplasmic reaction for MIB-1. In FNAB and intra-operative examination HTA is usually misdiagnosed as a papillary carcinoma. Histological examination of paraffin-embedded material and immunohistochemical stainings provide a correct diagnosis.