GIANT-CELL REPARATIVE GRANULOMA OF THE DISTAL SKELETAL BONES - A REPORT OF 5 CASES WITH IMMUNOHISTOCHEMICAL FINDINGS

Giant cell reparative granuloma (GCRG) is a reactive bone lesion that most often involves the jaws. However, occasional cases of GCRG in the distal. extremities have been reported, to which we add five cases. A ll the patients were young to middle-aged adults and had sharply borde red, lytic lesions. Histologically, all the lesions had areas of osteo clast-like giant cells and osteoblast mantled osteoid. Two of the case s had foci of osteoclast-like giant cells lining vascular spaces. In e xtragnathic locations, GCRG may simulate other osteolytic giant cells lesions such as giant cell tumour of bone and aneurysmal bone cy st (A nBC). Immunohistochemically, all cases showed positive staining of the strornal spindle cells for vimentin and actin, and of the osteoclast- like giant cells for CD68, vimentin and leucocyte common antigen. GCRG is a benign lesion and conservative therapy is curative. As GCRG may have histological features which resemble AnBC it may be considered to be the solid variant of AnBC.