Multinucleated giant cells in thyroid neoplasms. A cytologic, histologic and immunohistochemical study.

OBJECTIVE

To evaluate the presence of multinucleated foreign body-type giant cells (MGCs) in papillary carcinoma (PC), follicular variant of papillary carcinoma (FV) and follicular adenomas (FA) and to investigate their origin by immunoperoxidase studies.

STUDY DESIGN

The cytologic and histologic material of 10 PCs, 8 FVs, and 11 FAs were evaluated for the presence of MGCs. The immunohistochemical staining pattern of MGCs in paraffin-embedded tissue was studied using cytokeratin, epithelial membrane antigen, thyroglobulin, vimentin, A-1 antichymotrypsin, lysozyme and CD68.

RESULTS

MGCs were demonstrated in 10/10 PCs, 5/8 FVs and 0/11 FAs. In the immunostained sections, MGCs were negative for epithelial markers and positive for histiocytic markers.

CONCLUSION

These results indicate that MGCs are histiocytic and frequently present in PCs and FVs and usually absent from FAs.