Giant Cell Tumors of the Skull Base: Case Series and Current Concepts

Abstract

Objective: To study the clinical features, tumor characteristics and outcomes of giant cell tumors (GCTs) in the skull base based on long-term follow-up. We also report the largest series of GCTs in the temporal bone and the lateral skull base. Materials and Methods: A retrospective study was conducted of all GCTs managed at the Gruppo Otologico, a quaternary referral skull base institute, in Italy from 1993 to 2013. The clinical features, investigations, surgical management and follow-up were recorded. The surgical approaches used were infratemporal fossa approach (ITFA) type B and D and middle cranial fossa (MCF) approaches. Results and Observations: A total of 7 patients with GCTs of the skull base were treated at our institution. The principal complaints were hearing loss reported in 6 (85.71%) patients, tinnitus in 5 (71.43%) and swelling in 3 (42.9%). Pure-tone audiometry showed conductive hearing loss in 5 (71.43%) patients. High-resolution CT scan and MRI with gadolinium enhancement were done in all patients. Radiology showed involvement of the ITF and middle ear in 6 (85.71%) patients each, temporomandibular joint in 4 (57.14%) patients, invasions of the squamous part of the temporal bone, mastoid, MCF and greater wing of sphenoid in 3 (42.9%) patients each and the petrous bone in 2 (28.6%) patients. ITFA type B was applied as an approach for tumor removal in 5 (71.43%) patients, including a case where an additional MCF approach was employed, and ITFA type D and the transmastoid approach were applied in 1 (14.3%) patient each. Total tumor removal and successful cure was achieved in 6 (85.71%) patients. Subtotal removal leading to recurrence and eventual mortality was the result in 1 (14.3%) patient. Conclusions: A thorough knowledge of the anatomy of the skull base and the various skull base approaches is necessary to tackle GCTs. ITFA type B and D combined with MCF approaches provide good exposure of the tumor with minimal postoperative sequelae and good locoregional control. Recurrence due to either subtotal removal or suboptimal treatment may have disastrous consequences for the patient.

Surgical Management of Giant Cell Tumors in Temporomandibular Joint Region Involving Lateral Skull Base: A Multidisciplinary Approach

“…The median age of the skull base GCT patients (41 years) was close to the age distribution reported in patients with GCTs occurring in the extremities. 3,10 However, contrary to other studies, 17,19 there was a slight male preponderance in our study. About one third of our cases (32.1%) were referred to us for treatment of recurrent GCTs, which is indicative of the increased tendency for recurrence when undertreated.…”

“…As a direct consequence of the intracranial extension, cranial nerve neuropathy will cause severe morbidity. 19,20 Because most GCTs in our series already extended into the brain parenchyma (n = 19, 67.9%), neurologic symptoms, such as facial dysesthesia, hearing debilitation, and headache, were not rare in this retrospective study. The median age of the skull base GCT patients (41 years) was close to the age distribution reported in patients with GCTs occurring in the extremities.…”

“…Silvers et al 22 reported that GCTs of the skull bones lacked the characteristic signs of expansion and the ''soap bubble'' appearance. 19 However, we contended that when GCTs originated from or extended to the skull base, rapid osteolytic changes would occur and tumors would no longer be confined within the bony structures. Remarkable extraosseous extension with ill-defined contours would be the typical features displayed in this specific region, as confirmed in our findings.…”

“…4,10,14,15,19 The choices of different types of surgical interventions are controversial owing to the heterogeneity and rarity of the disease. Traditionally, many surgeons advocated treating GCTs in the long bones with intralesional curettage combined with high-speed burring to improve the thoroughness of tumor removal.…”

Benign Tumors of Temporomandibular Joint

“…Intralesional curettage is not recommended for GCTs in the skull base because recurrence in this location would complicate further treatment and make it unresectable for reoperation [72]. However, because of the complexity of the craniofacial anatomy, wide excisions or en bloc resections for head and neck GCTs should be attempted.…”