CD68 and Granuloma: Furthermore, immunohistochemical staining of CD68 showed that detection of CD68-expressing macrophages was similar in irradiated and nonirradiated adjacent cryosections, with macrophages located in cellular regions of granulomas as well as next to the fibrous rim of necrotizing granulomas (Fig. 3C), demonstrating that irradiation has no major impact on the integrity of cells such as macrophages.