✓ Juxtafacet cysts of the lumbar spine have been reported with increasing frequency but their pathogenesis remains obscure. These cysts most frequently present with back pain, followed by chronic progressive radiculopathy or gradual onset of symptoms of spinal canal compromise. The authors report an unusual case of hemorrhage into a right L3–4 synovial cyst causing an acute cauda equina syndrome and describe its successful surgical treatment. The clinical, radiographic, and pathological features are discussed.
Stephen B. Tatter and G. Rees Cosgrove
Report of two cases
Stephen B. Tatter, Lawrence F. Borges and David N. Louis
✓ Central neurocytoma is a neuronal neoplasm that occurs supratentorially in the lateral or third ventricles. The authors report the clinical, neuroradiological, and neuropathological features of two neurocytomas arising in the spinal cord of two men, aged 65 and 49 years. The patients presented with progressive neurological deficits referable to the cervical spinal cord. Magnetic resonance imaging revealed isodense intramedullary spinal cord tumors at the C3–4 level. Both tumors were initially misdiagnosed as gliomas. In Case 1 the correct diagnosis was made after electron microscopy revealed neuronal features. Immunostaining in Case 2 revealed that tumor cells were positive for synaptophysin and negative for glial fibrillary acidic protein, strongly indicating a neuronal tumor. It is suggested that this spinal cord neoplasm be included under the designation “central neurocytoma.”
Stephen B. Tatter, Christopher S. Ogilvy, Jeffrey A. Golden, Robert G. Ojemann and David N. Louis
✓ Two cases are reported of third ventricle masses that were clinically and radiographically indistinguishable from pure colloid cysts. A 21- and a 36-year-old man presented with 5-year and 10-day histories of headache, respectively. Magnetic resonance (MR) imaging revealed smooth, homogeneous masses in the anterior third ventricle that were iso- to hyperintense on T1-weighted MR images and hyperintense on T2-weighted images. There was little enhancement with intravenous contrast material. In both patients, craniotomies were performed and histopathological examination revealed xanthogranulomas of the choroid plexus with only microscopic foci of colloid cyst-like structures. These cases illustrate that xanthogranulomas of the third ventricle may clinically and radiologically mimic pure colloid cysts, that a range of MR imaging signals can be seen, and that craniotomy rather than stereotactic aspiration is the indicated treatment.
Ann Liu, Elizabeth N. Kuhn, John T. Lucas Jr., Adrian W. Laxton, Stephen B. Tatter and Michael D. Chan
Neurofibromatosis Type 2 (NF2) is a rare autosomal dominant disorder predisposing patients to meningiomatosis. The role of stereotactic radiosurgery (SRS) is poorly defined in NF2, and although the procedure has excellent control rates in the non-NF2 population, its utility has been questioned because radiation has been hypothesized to predispose patients to malignant transformation of benign tumors. To the authors' knowledge, this is the first study to examine the use of SRS specifically for meningiomas in patients with NF2.
The authors searched a tumor registry for all patients with NF2 who had undergone Gamma Knife radiosurgery (GKRS) for meningioma in the period from January 1, 1999, to September 19, 2013, at a single tertiary care cancer center. Medical records were retrospectively reviewed for patient and tumor characteristics and outcomes.
Among the 12 patients who met the search criteria, 125 meningiomas were identified, 87 (70%) of which were symptomatic or progressive and thus treated with GKRS. The median age at the first GKRS was 31 years (interquartile range [IQR] 27–37 years). Five patients (42%) had multiple treatments with a median of 27 months (IQR 14–50 months) until the subsequent GKRS. The median follow-up in surviving patients was 43 months (IQR 34–110 months). The 5-year local tumor control and distant treatment failure rates were 92% and 77%, respectively. Toxicities occurred in 25% of the GKRS treatments, although the majority were Grade 1 or 2. At the last follow-up, 4 patients (33%) had died a neurological death at a median age of 39 years (IQR 37–46 years), and their cases accounted for 45% of all tumors, 55% of all treated tumors, and 58% of all GKRSs. Univariate analysis revealed several predictive variables for distant failure, including male sex (HR 0.28, 95% CI 0.086–0.92, p = 0.036), age at distant failure (HR 0.92, 95% CI 0.90–0.95, p < 0.0001), and prior number of GKRS treatments (HR 1.2, 95% CI 1.1–1.4, p = 0.0049). Local failure, maximum size of the treated tumor, delivered tumor margin dose, and WHO grade were not significant. On multivariate analysis, age at distant failure (HR 0.91, 95% CI 0.88–0.95, p < 0.0001) and prior number of GKRSs (HR 1.3, 95% CI 1.1–1.5, p = 0.004) remained significant. No malignant transformation events among treated tumors were observed.
Radiosurgery represents a feasible modality with minimal toxicity for NF2-associated meningiomas. Increasing patient age was associated with a decreased rate of distant failure, whereas an increasing number of prior GKRS treatments predicted distant failure. Further studies are necessary to determine the long-term patterns of treatment failure in these patients.
E. Andrew Stevens, Alexander K. Powers, Thomas A. Sweasey, Stephen B. Tatter and Robert G. Ojemann
The authors describe a method of harvesting autologous pericranium for duraplasty in patients with Chiari malformation Type I (CM-I) that avoids excessive exposure or a second incision. Nonautologous dural grafts have been associated with numerous complications including hemorrhage, bacteria and virus transmission, fatal Creutzfeldt-Jakob disease transmission, foreign body reaction, systemic immune response, excessive scarring, slower healing, premature graft dissolution, and wound dehiscence. Autogenous tissues have the advantage of being nonimmunogenic, nontoxic, readily available, and inexpensive. Pericranium is a preferred substrate because it is flexible, strong, and easily sutured for a watertight closure. Current literature supports the use of autogenous pericranium for dural grafting in CM-I procedures, but has heretofore failed to provide a method of harvest that avoids the complications associated with a larger exposure or second incision. The authors offer a simple alternative technique for using local pericranium in duraplasty for CM-I or other posterior fossa abnormalities.
William J. Triffo, J. Daniel Bourland, Daniel E. Couture, Kevin P. McMullen, Stephen B. Tatter and Padraig P. Morris
Vein of Galen aneurysmal malformations (VGAMs) are uncommon congenital malformations arising from fistulous communication with the median vein of the prosencephalon, a primitive precursor of midline cerebral venous structures. Angiographic embolization is the primary modality for treatment given historically poor microsurgical outcomes. Only a few reports of treatment by Gamma Knife radiosurgery (GKRS) exist in the literature, and the results are variable. The authors present 2 cases of VGAM in which GKRS provided definitive treatment with good outcome: one case involving antenatal presentation of a high-output, mural-type VGAM with complex clinical course refractory to multiple embolic procedures, and the other a choroidal-type VGAM presenting with hemorrhage in an adult and without a feasible embolic approach. With discussion of these cases and review of the literature, the authors advocate inclusion of GKRS as a therapeutic option for treatment of these complex lesions.
Alexander K. Powers, Matthew T. Neal, Louis C. Argenta, John A. Wilson, Anthony J. DeFranzo and Stephen B. Tatter
The aim in this study was to describe the safety and efficacy of vacuum-assisted closure (VAC) in patients with complex cranial wounds with extensive scalp, bone, and dural defects who were not candidates for immediate free tissue transfer. Five patients (4 men and 1 woman) ages 24–73 years with complex cranial wounds were treated with VAC at Wake Forest Baptist Medical Center. Etiologies included trauma, squamous cell carcinoma, and malignant meningioma. Cutaneous wound defects measured as large as 15 cm in diameter. Four of the 5 patients had open skull defects with concomitant dural defects, and 1 patient had dural dehiscence. After surgical debridement, all 5 patients were treated with the direct application of a VAC device to a reapproximated dura mater (1 patient), to a pericranial flap (1 patient), or to a regenerative tissue matrix overlying CNS tissue (3 patients). In all cases involving open cranial wounds, the VAC device promoted granulation tissue formation over the dural substitute, prevented CSF leakage, and kept the wounds free from local infection. The duration of VAC therapy ranged from 16 to 91 days. Although VAC therapy was intended as a temporary measure until these patients could be stabilized for larger tissue transfer procedures or they succumbed to their primary pathology, 1 patient had a successful skin graft following VAC therapy. Hydrocephalus requiring shunt placement developed in 2 patients during VAC therapy. The VAC dressings applied to a tissue matrix or other barrier over brain tissue in extensive cranial wounds are safe and well tolerated, providing a functional barrier and preventing infection.
James L. West, Michael H. Soike, Jaclyn J. Renfrow, Michael D. Chan, Adrian W. Laxton and Stephen B. Tatter
Rathke’s cleft cysts (RCCs) are benign lesions of the sella turcica that usually come to neurosurgical attention due to compression of the optic apparatus (OA) and headaches. Treatment options for these lesions include observation, aspiration of cyst contents, or open resection of the cyst with the cyst wall. All of these options involve the potential for cyst recurrence or enlargement. In this study the authors report on a potential new therapeutic option for RCCs, i.e., stereotactic radiosurgery (SRS).
A retrospective review was conducted of 5 patients with histologically confirmed, multiply recurrent RCCs who were treated with single-fraction SRS at a tertiary referral academic medical center.
The total cohort consisted of 5 female patients with an average age of 31.8 years. The most common presenting symptom was headache followed by blurry vision. The symptoms were present on average for 7 months before intervention. The median number of surgeries prior to radiosurgery was 2. The average volume of lesion treated was 0.34 cm3. The median SRS dose was 12.5 Gy prescribed to the 50% isodose line with an average prescription coverage of 96.6%. The median dose to the OA was 5 Gy. At last follow-up, 3 of 5 cysts had completely regressed, 1 had regressed by more than 50% but was still present, and 1 was stable, with an overall mean follow-up duration of 34.2 months. There were no neurological, endocrinological, or visual complications attributable to SRS during the follow-up period.
RCCs can be a challenging clinical entity to treat, especially when they are multiply recurrent. In patients with an average of 2 previous surgeries for resection, a single SRS session prevented recurrence universally, with an average follow-up of almost 3 years. These results indicate that further investigation of the treatment of RCCs with SRS is indicated.
Elizabeth N. Kuhn, Glen B. Taksler, Orrin Dayton, Amritraj G. Loganathan, Tamara Z. Vern-Gross, J. Daniel Bourland, Adrian W. Laxton, Michael D. Chan and Stephen B. Tatter
The purpose of this study was to evaluate patterns of failure after stereotactic radiosurgery (SRS) for meningiomas and factors that may influence these outcomes.
Based on a retrospective chart review, 279 patients were treated with SRS for meningiomas between January 1999 and March 2011 at Wake Forest Baptist Health. Disease progression was determined using serial imaging, with a minimum follow-up of 6 months (median 34.2 months).
The median margin dose was 12.0 Gy (range 8.8–20 Gy). Local control rates for WHO Grade I tumors were 96.6%, 84.4%, and 75.7% at 1, 3, and 5 years, respectively. WHO Grade II and III tumors had local control rates of 72.3%, 57.7%, and 52.9% at 1, 3, and 5 years, respectively. Tumors without pathological grading had local control rates of 98.7%, 97.6%, and 94.2% at 1, 3, and 5 years, respectively. Of the local recurrences, 63.1% were classified as marginal (within 2 cm of treatment field). The 1-, 3-, and 5-year rates of distant failure were 6.5%, 10.3%, and 16.6%, respectively, for Grade I tumors and 11.4%, 17.2%, and 22.4%, respectively, for Grade II/III tumors. Tumors without pathological grading had distant failure rates of 0.7%, 3.2%, and 6.5% at 1, 3, and 5 years, respectively. Wilcoxon analysis revealed that multifocal disease (p < 0.001) and high-grade histology (WHO Grade II or III; p < 0.001) were significant predictors of local recurrence. Additionally, male sex was a significant predictor of distant recurrence (p = 0.04). Multivariate analysis also showed that doses greater than or equal to 12 Gy were associated with improved local control (p = 0.015).
In this patient series, 12 Gy was the minimum sufficient margin dose for the treatment of meningiomas. Male sex is a risk factor for distant failure, whereas high-grade histology and multifocal disease are risk factors for local failure.