Histologically, the lesions consisted of a proliferation of mature<unk>  cells and reticulo-endothelial cells supported by a stroma of granulation tissue, with varying degrees of myxoid change or collagenization. Angioinvasion within the lesion is observed in 50% of cases. Immunohistochemical staining reveals the IgG-predominant polyclonal nature of the<unk>  cells, indicating a reactive inflammatory process rather than a neoplastic one. Electron microscopy confirms the benign nature of the<unk>  cells with fibroblast and myofibroblast proliferation admixed with that of other inflammatory cells.
Plasma cell granuloma
Central giant-cell granuloma
Peripheral giant-cell granuloma
Eosinophilic granuloma
Perifollicular mucinosis
Annular elastolytic giant-cell granuloma
Xanthogranulomatous inflammation
Fibrin ring granuloma