Treatments for GCRG include complete surgical resection, corticosteroid injection, calcitonin therapy, and radiation therapy.
Differential diagnosis between GCRG and GCT is quite challenging.
Based on the imaging appearance, GCRG and GCT are difficult to distinguish; however, they have several differences.
Other points for distinguishing between GCRG and GCT include: 1) onset age: GCRG generally occurs between 10 and 20 years of age, while GCT occurs frequently in patients between 20 and 40 years of age and rarely below the age of 20 years; 2) occurrence site: mandible and maxilla are common sites for GCRG, which is rarely observed on other bone.
The microscopic features of GCRG are identical to those of ABC with proliferating spindle cells arranged in a haphazard fashion embedded in fibrous to myxoid matrix.
The differential diagnosis for GCRG includes other giant cell-rich lesions, such as giant cell tumor of bone and low-grade intramedullary osteosarcoma.
Low-grade osteosarcoma is a more ominous entity to be differentiated from GCRG. Like GCRG, low-grade osteosarcoma may occur in the patient's third decade and is commonly seen about the knee.
It is likely that some of the lesions diagnosed as fibrous histiocytoma and GCRG are really regressing NOF.
Although GCRG of the temporal bone has been purported to be a reaction to cranial trauma, (1,2,11,12) its pathogenesis remains unclear.
In this article, we report a new case of temporal bone GCRG, in which a large tumor infiltrated the sphenoid bone, infratemporal fossa, pterygoid fossa, temporomandibular joint, middle cranial fossa, and temporal lobe.
The definitive histology revealed that the tumor was a GCRG. The patient was scheduled to undergo a complete removal of the lesion, but unfortunately she and her mother refused the recommended surgery.
The reported symptoms of GCRG of the temporal bone include heating loss, tinnitus, a palpable mass, pain, vertigo, and facial weakness.