The Expression of Tumor-Associated Macrophages and Multinucleated Giant Cells in Papillary Thyroid Carcinoma

Inflammation that occurred in the tumor microenvironment was characterized by abundant macrophage infiltration, playing role in innate immunity. Multinucleate giant cells (MGCs) occur in a variety of inflammatory, hyperplastic, and neoplastic thyroid disorders. They also have been recognized as a feature of papillary thyroid carcinoma (PTC).

The aim of this study was to evaluate cases of PTC for the presence of macrophages, and estimate CD68+ TAMs density in tumor stroma, margin and the surrounding tissue. We assessed also MGCs.

Macrophages and MGCs densities were correlated with clinicopathologic parameters to assess the possible prognostic significance. We investigated 56 patients immunohistochemically and immunofluorescence with antibodies against CD68 and IL-17.

A statistically significant correlation was established between PTC patients in III stage, containing many MGCs, and PTC in I and II stage, with many MGCs. Eighty Percent of patients in III stage showed many MGCs in comparison with patients in I and II stage, where many MGCs were found only in 21,1% (χ² = 6.189, p = 0.013).

Our study demonstrates that the increased density of MGCs is associated with advanced stage of PTC, and therefore with tumor progression and that cases of PTC should be carefully screened for their presence.