Giant Cell Reparative Granuloma of the Cranial Vault: Exceptional Bone Lesion

Abstract

Giant cell reparative granuloma (GCRG) is an uncommon nonneoplastic lesion of bone. It is even rarer in the bones of the skull, particularly in the calvarial bones. Originally considered to be peculiar to the jawbones, GCRG has been described in some other locations, such as the short tubular bones of the hand and the facial (paranasal) bones. Only one GCRG has been found in the skull, this one in the temporal bone. The authors were unable to find a report of such a lesion in the bones of the calvarium. The etiology of GCRG is unknown, but it is believed to result from a traumatic intraosseous hemorrhage or periosteal reaction. A GCRG was diagnosed in a 31-month-old male infant who presented with a nonpainful, slow-growing, right frontal swelling, apparently related to a head contusion that had occurred 21 months earlier. The lesion was removed surgically. The main differential diagnosis is giant cell tumor.

Giant Cell Reparative Granuloma of the Temporal Bone: Neuroradiological and Immunohistochemical Findings. Case Report.

“…T 2 -weighted MR imaging of GCRG, GCT, and PVNS demonstrates extremely low intensity, 10,11,14,18,19,24,34,35) whereas the other tumors usually appear as high intensity. We consider that this finding is very important in the differential diagnosis.…”

“…20) Although only 21 cases of GCRG involving the skull have been reported (Table 1), 1,[4][5][6]12,14,17,22,[24][25][26][27]30,34,[37][38][39]41) this lesion may actually be more common than supposed because it may be unrecognized, unreported, or misclassified as GCT. 17) The preoperative differential diagnosis of GCRG includes such skull tumors as GCT, metastatic cancer, sarcoma, malignant lymphoma, brown tumor of hyperparathyroidism, aneurysmal bone cyst, pigmented villonodular synovitis (PVNS), and fibrous dysplasia.…”

Large Giant Cell Reparative Granuloma of the Petrous Bone. Case Report.

“…14) Inadequate information is available to correctly manage this tumor. 8,11,12) All giant cell lesions of the temporal bone were regarded as giant cell tumors (GCTs). 7,12) However, the differential diagnosis of GCRG from GCT is important because the biologic behaviors are quite different.…”

“…12) The first case of GCRG was located in the mandible and maxilla. 14) Subsequently, GCRG has occurred in many sites including the orbit, 19) cranial vault, 11) temporal bones, 1,2,8,12,15,17) sphenoid bone, ethmoid bone, 24) facial bones, 4,20) and short and long bones of the axial skeleton. 5,8) GCRG has recurred in the intracranial region or cranial vault.…”

“…3,8,12,15) GCRG may not be a neoplasm but a reactive and reparative mass to past episodes such as trauma and unknown events. 5,8,[10][11][12]23) Extensive surgical removal is recommended, since the tumor is benign, 21) and leads to a complete cure. However, a presumptive diagnosis of GCRG is extremely difficult to make before surgery.…”