Eosinophilic Granuloma of the Cervical Spine in Adults: A Review.

OBJECTIVE: Spinal eosinophilic granulomas (EGs) are uncommon tumors, constituting <1% of all bone tumors. They are mostly seen in the pediatric age group, whereas adult onset is rare. The cervical spine is an infrequent location for EG. The literature is sparse regarding the clinical and management aspects of these lesions, especially in adults. METHODS: A literature review was performed by searching online databases to analyze all the reported cases of adult-onset cervical EG. RESULTS: Sixty-two cases were identified and analyzed. The male/female ratio was 3.1:1. The mean age at presentation was 32.8 years (range, 18-71 years). Neck pain, limb weakness, and restriction of movement were the most frequent symptoms. The C2 vertebra was the most frequently involved. The vertebral body was involved in >80% of patients and only 2 had vertebra plana morphology. The cervical lesions involved single vertebra in 42 patients (82%), whereas 9 patients (18%) had multiple vertebral involvement. Fifteen patients were managed conservatively, of whom 7 failed and required surgery later; 40 patients underwent definitive surgery and 17 received adjuvant treatment. Posterior-only surgeries were performed in 5 patients, anterior-only in 20, and circumferential in 14. The mean follow-up duration was 68 months (range, 12-268 months). The outcome was good to excellent in all, except 1, irrespective of type of treatment received. CONCLUSIONS: Cervical spine EG is rare in adults and usually presents as an osteolytic lesion involving the vertebral body; vertebra plana is very rare. Surgery is typically reserved for patients with severe neurologic deficits and bony instability. The outcome seems good in most cases.

Gamma Knife radiosurgery in the treatment of abducens nerve schwannomas: a retrospective study.

OBJECTIVE Of the intracranial schwannomas, those arising from the vestibular nerves are the most common. Abducens nerve (AN) schwannomas are very rare, and there is limited literature on their optimal management. Therapeutic options include surgery and/or stereotactic radiosurgery. The aim of this study was to evaluate the role of Gamma Knife radiosurgery (GKRS) in these sixth cranial nerve (CN) schwannomas. METHODS The authors performed a retrospective analysis of patients who had undergone GKRS for intracranial tumors at their institute in the period from 2003 to 2010. Inclusion criteria were as follows: isolated AN paresis on presentation, a lesion along the course of the sixth CN, and imaging features characteristic of a schwannoma. Patients with other CN deficits and neurofibromatosis Type 2 were excluded. Symptomatic improvement was defined as the resolution of or an improvement in diplopia noted on a subjective basis or as an improvement in lateral eyeball excursion noted objectively on follow-up. A reduction in tumor volume by at least 20%, as noted by comparing the pre- and post-GKRS images, was deemed significant. RESULTS Six patients with a mean age of 37.1 years (range 17-55 years) underwent primary GKRS. There were 2 prepontine cistern, 3 cavernous sinus, and 1 cisterno-cavernous tumor. The mean duration of symptoms was 6.1 months (range 3-12 months). The mean tumor volume was 3.3 cm3 (range 1.5-4.8 cm3). The mean tumor margin radiation dose was 12.5 Gy (range 12-14 Gy), while the median margin dose was 12 Gy (50% isodose line). The median number of isocenters used was 5 (range 4-8). The brainstem received an average 8.35-Gy radiation dosage (range 5.5-11 Gy). The mean follow-up duration was 44.3 months (range 24-78 months). Symptoms remained stable in 1 patient, improved in 3, and resolved in 2 (total improvement 83%). Magnetic resonance imaging at the last follow-up showed a stable tumor size in 3 patients (50%) and a reduction in the other 3. Thus, the tumor control rate achieved was 100%. No new CN deficits were noted. CONCLUSIONS Abducens nerve schwannomas are rare intracranial tumors. They can be cavernous, cisternal, or cisterno-cavernous in location. Excellent tumor control rates and symptomatic improvement can be achieved with GKRS, which appears to be a safe and effective, minimally invasive modality for the treatment of such lesions. Therefore, it is reasonable to consider GKRS as the initial treatment of choice for this rare pathology. Long-term follow-up will be essential for further recommendations.