Ductal carcinoma in situ of the breast with osteoclast-like giant cells: A case report with immunohistochemical analysis

Abstract Breast carcinoma with osteoclast-like giant cells (OGCs) is extremely rare. OGCs are found mostly in invasive breast carcinoma and ductal carcinoma in situ is extremely rare. We report a case of ductal carcinoma in situ with osteoclast-like giant cells of the breast (DCIS OGCs) in a 38-year-old female. Histologically, on a low-power view, the DCIS OGCs exhibited a solid pattern with thick fibrovascular stroma. On a high-power view, the tumor cells showed indistinct and eosinophilic cytoplasm, and round to oval nuclei with prominent nucleoli. Most OGCs were identified within the space formed by tumor cells and consisted of multiple nuclei with abundant eosinophilic cytoplasm. Immunohistochemically, p63 and α-smooth muscle actin were positive in a myoepithelial layer around the in situ component. The OGCs stained positive for CD68, vascular endothelial growth factor and tumor necrosis factor-α, but were negative for cytokeratin AE1/AE3, CD163, and transforming growth factor-β. We could not find vessel proliferation around the OGC and this may be different from OGCs in invasive breast cancer. Our IHC results suggest that OGCs are anti-tumoral M1-like macrophages and that they express antitumor effects on cytokines in DCIS OGCs. Previous and current data suggest the existence of both antitumor and protumor OGCs in breast carcinoma, whereby the phenotype is possibly influenced by tumor invasiveness.