Bone metastases of differentiated and medullary thyroid gland carcinomas. Usefulness and limitations of immunohistology performed on undecalcified plastic-embedded tissue specimens.

Undecalcified methylmethacrylate(MMA)-embedded biopsies and surgical specimens from 20 bone metastases of differentiated or medullary thyroid carcinomas or prostate carcinomas were investigated immunohistologically for the presence of thyroglobulin, cytokeratin, vimentin, and CEA. The immunoreactions on MMA-sections revealed the same staining patterns as those demonstrated using paraffin sections of the primary lesions. Conversely, immunohistological examination of decalcified paraffin-embedded specimens of the same metastases yielded either false-negative results or results that did not allow an exact evaluation. The findings demonstrate the usefulness and limitations of immunohistology when performed on undecalcified plastic-embedded material.