Giant Cell Reparative Granuloma

Abstract

Giant cell reparative granuloma (GCRG) is a rare benign giant cell-rich tumorlike reactive lesion with a predilection for craniofacial skeleton (gnathic) and small bones of the hands and feet (extragnathic). It is not a true neoplasm, but rather a reactive process. Early in 1953, Jaffe [1] first described GCRG as a benign nonneoplastic process peculiar to jawbones related to intraosseous hemorrhage, which contains multinucleated giant cells in a predominantly fibroblastic stroma. Years later, Ackerman and Spjut [2] reported two similar lesions occurring in the phalanges of the hand, and they named it “giant cell reaction.” Decades later, Lorenzo and Dorfman [3] reported eight additional cases involving hands and feet with high recurrence rate of 50% and added term “reparative” to “giant cell reaction” to represent a reactive process to hemorrhage. They proposed to name the lesions as “extragnathic GCRG.” Sanerkin and colleagues [4] reported non-cystic lesion involving the spines and ethmoid, with morphologic similarity to that in aneurysmal bone cyst (ABC) and overlapped histology with GCRG. They regarded this lesion as a variant of ABC devoid of a cystic “blowout” and referred to it as a “solid ABC.” There has been some controversy regarding the nomenclature of the particular lesion. More recently, GCRG is regarded as synonymous with solid variant of ABC in extragnathic sites because of indistinguishable morphologic findings and high rate of positive USP6 gene rearrangements as in ABC [5].