Hybrid central giant cell granuloma and central odontogenic fibroma-like lesions of the jaws.

Ten lesions from eight cases are presented of a rare intra-osseous jaw lesion with the combined histological features of giant cell granuloma and central odontogenic fibroma. Lesions arose over a wide age range and presented as monolocular or multilocular radiolucencies with cortical expansion and, in one case, perforation. Two lesions recurred after curettage, one being eradicated by a second curettage and one by conservative excision. Histologically, zones of typical giant cell granuloma lay in a fibrous stroma containing islands, strands and clusters of epithelial cells. Islands often contained duct-like spaces or hyaline basement membrane globules. Trabeculae of osteoid were present in five lesions. Recurrent lesions showed features identical to the initial lesion, including recurrence of the prominent epithelial component. These features cannot be conclusively ascribed to a variant of either giant cell granuloma, central odontogenic fibroma or aneurysmal bone cyst, but the clinical features are slightly more suggestive of giant cell granuloma. Attention is drawn to the characteristic and potentially confusing histological appearances. The presence of giant cell granuloma-like areas in central odontogenic fibroma-like lesions is associated with an increased risk of recurrence following curettage.