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

Abstract

A 38-year-old man presented with a giant cell reparative granuloma (GCRG) of the left temporal bone. Computed tomography showed a osteolytic middle cranial mass lesion. Magnetic resonance (MR) imaging showed the lesion as low intensity with heterogeneous enhancement by gadolinium on the T 1 -weighted images, and extremely low intensity on the T 2 -weighted images. Angiography showed the lesion as highly vascular and fed by branches of the left external carotid artery. After preoperative embolization, gross total removal of the tumor was performed. The postoperative course was uneventful and no evidence of recurrence has been found for more than 4 years. Histological examination revealed GCRG with multinucleated giant cells in the fibrous background, abundant collagen bundles, hemosiderin deposits, and trabeculae of reactive bone. Some of the mononuclear stromal cells and almost all of the giant cells were positive for CD68, suggesting histiocytic differentiation. These histological features reflect the marked decrease in signal intensity on T 2 -weighted MR images.

A Giant Cell Granuloma of the Temporal Bone: A Case Report

“…MGCs of extracranial GCT and GCG are immunohistologically positive for CD 68, and shows histiocytic differentiation [6]. We also detected CD68 positive cells in the presented case, and P63 immunostaining may use differentiating GCTs from GCGs, and it is positive in GCT [7].…”

“…We detected similar CT appearance in our patient with marginal sclerosis and solid-cystic components indicated remodeling and destruction ( Figure 1). MRI of GCGs show heterogenous intensity on both T1 and T2W images [6]. The presented patient also had mixed density in both T1 and T2W images, and contrast enhancement was heterogenous after contrast media injection (Figure 2).…”

“…Although the reported cases indicate that the biological behavior of GCG involving the skull is benign, the preferred treatment is complete surgical excision with negative tumor margin [6]. But this is not possible all time due to the involvement of skull base bones.…”

“…In recurrent cases, attempting total surgical excision must be thought. Although radiotherapy is another option for recurrent tumors, malignant degeneration has been reported after radiotherapy in 7-29% of the cases and had no proved effect on local control of the tumor [6].…”

Giant cell tumor of the temporal bone with intratumoral hemorrhage

“…The presence of osseous metaplasia favors a diagnosis of GCRG. The presence of hemosiderin pigment is thought to be one of the most important findings differentiating GCRG from GCT, 8,34,35 because perivascular hemorrhage and hemosiderin deposition are believed to occur to a lesser extent in GCT than in GCRG. Areas of decreased MR signal intensity caused by the presence of hemosiderin deposits are considered to represent the radiographic identifying feature of GCRG, given that GCRG may be more likely to involve hemorrhage and inflammation.…”