Faculty Bibliography

BACKGROUND: The treatment of central nervous system (CNS) germ cell tumors (GCT) remains controversial. The purpose of this study was to demonstrate efficacy of a chemotherapy only strategy, with less morbidity, when compared to regimens with irradiation. METHODS: Between January 2001 and December 2004 newly diagnosed patients with CNS GCT were treated with one of two risk-tailored chemotherapy regimens. Twenty-five patients aged 4 months to 24.5 years were stratified: Regimen A consisted of 4-6 cycles of carboplatin/etoposide alternating with cyclophosphamide/etoposide for low risk (LR) localized germinoma with normal cerebrospinal fluid (CSF) and serum tumor markers. Regimen B consisted of 4-6 cycles of carboplatin/cyclophosphamide/etoposide for intermediate-risk (IR) germinoma with positive human chorionic gonadotrophin-beta (HCGbeta) and/or CSF HCGbeta <50 mIU/ml and high-risk (HR) biopsy-proven non-germinomatous malignant elements (MMGCT) or elevated serum/CSF alpha-fetoprotein and/or HCGbeta serum/CSF >50 mIU/ml. RESULTS: Eleven patients were classified as LR, 2 IR, and 12 HR. Seventeen (68%) patients achieved complete radiographic and marker responses after two courses and 19 (76%) after four courses of chemotherapy. Eleven patients relapsed at a mean of 30.8 months; eight of them subsequently received irradiation. The 6-year event free and overall survival for the 25 patients was 45.6% and 75.3%, respectively. CONCLUSION: These intensive chemotherapy regimens proved less effective than irradiation containing regimens. Our results indicate that, at the present time, standard treatment for CNS GCT continues to include irradiation either alone or combined with chemotherapy for pure germinomas and with chemotherapy for those with MMGCT

OBJECT: Given the potential morbidity of cranial irradiation in young children, the risk-benefit analysis of limited surgery plus irradiation versus radical resection may favor the latter strategy. The purpose of this study was to assess the oncological, endocrinological, and functional outcomes of patients 5 years of age and younger who underwent radical resection of craniopharyngiomas. METHODS: Between 1991 and 2008, 19 children age < or = 5 years were diagnosed with a craniopharyngioma and underwent radical resection by the senior author (J.H.W.). Data were retrospectively collected on these 19 patients (11 males, 8 females; mean age 3.2 years) to assess the efficacy and impact of surgical treatment. RESULTS: Eighteen (95%) of 19 patients underwent gross-total resection (GTR) confirmed by intraoperative inspection and postoperative imaging. There was no operative death and 18 of (95%) 19 patients were alive at a mean follow-up of 9.4 years (median 8.3 years). Six patients (31%) had a total of 7 tumor recurrences treated by repeat GTR in 5 patients and Gamma knife surgery in 1 patient. No patient required conventional, fractionated radiation therapy. Disease control was achieved surgically in 17 (89.5%) patients and with surgery and Gamma knife surgery in 1 patient, yielding an overall rate of disease control of 95% without the use of conventional radiotherapy. New-onset diabetes insipidus occurred in 50% of patients. Vision worsened in 1 patient, and there was no long-term neurological morbidity. CONCLUSIONS: In this retrospective series, children aged < or = 5 years with craniopharyngiomas can have excellent outcomes with minimal morbidity after radical resection by an experienced surgeon. Disease control in this population can be successfully achieved with GTR alone in the majority of cases, avoiding the detrimental effects of radiotherapy in this vulnerable population

A choroid plexus papilloma is a rare CNS neoplasm arising from the neuroepithelial lining of the choroid plexus. A third ventricular location of a choroid plexus papilloma is rare compared with the more common sites in the lateral and fourth ventricles. Cystic choroid plexus papilloma represents an infrequent subtype that may present diagnostic ambiguity. The authors present a case of cystic choroid plexus papilloma within a cavum septum pellucidum that radiographically mimicked neurocysticercosis

OBJECT: The choice of surgical approach during resection of a thalamic juvenile pilocytic astrocytoma (JPA) is dictated by the location of the displaced normal thalamus and posterior limb of the internal capsule (PLIC). Diffusion tensor (DT) imaging and white matter tractography can identify the location of the PLIC in relation to the tumor and may be useful in planning the operative trajectory. METHODS: Diffusion tensor imaging was used to localize the PLIC on preoperative MR imaging in 6 children undergoing resection of thalamic JPAs. After review of the standard T2-weighted MR imaging sequences, the anticipated position of the PLIC was determined. This result was compared with the location of the PLIC determined by a blinded radiologist with the use of DT imaging. The utility of DT imaging in determining the surgical approach to a thalamic JPA, degree of resection, and neurological outcomes were all evaluated. RESULTS: Diffusion tensor imaging confirmed the expected location of the PLIC as approximated on conventional T2-weighted images in all 6 cases. In 1 patient in particular, unexpected medial deviation of the PLIC was identified, and this proved useful in tailoring the approach to a more lateral trajectory. Gross-total resection of all cystic and solid tumor components was confirmed on postoperative imaging in all cases. All patients experienced mild to moderate worsening of neurological status immediately following resection, but 4 of 6 patients were back to their preoperative baseline at 6-month follow-up. CONCLUSIONS: Diffusion tensor imaging and white matter tractography successfully identified the white matter fibers emanating from the precentral gyrus within the PLIC in children with thalamic JPAs prior to surgery. Diffusion tensor imaging served as a valuable tool for stereotactic planning of operative approaches to thalamic JPAs. Localizing the position of the PLIC helped minimize potential neurological morbidity and facilitated gross-total resection

We present a case of synchronous involvement of the pineal and suprasellar regions by a mixed germ cell tumor comprising germinoma and yolk sac tumor components, with a predominant angiomatous component. To our knowledge, it is the first case of this nature to be reported in the literature. Usually, synchronous lesions of this kind are pure germinomas, and some clinicians will forgo a biopsy and assume a germinoma histology if the serum beta-human chorionic gonadotrophin (HCG) is <50 IU/l and the alpha-fetoprotein (AFP) is within normal limits. Secondly, if a biopsy is performed on a lesion that has a prominent angiomatous component, the diagnostic germ cell tumor may be missed at the time of the biopsy. In order to alert clinicians and pathologists to this rare entity, the case is discussed with particular reference to difficulties that were encountered in rendering an accurate diagnosis, and the associated management implications

Local recurrence following radical resection is one of the most common complications of pediatric craniopharyngioma. Only 28 cases of ectopic recurrence of craniopharyngioma have been reported in the literature, and only 13 cases occurred in patients originally treated as children. In this consecutive series of 86 children who underwent radical resection of primary and recurrent craniopharyngiomas, 4 patients (4.7%) experienced ectopic tumor recurrence, accounting for 27% of all recurrences after gross-total resection. The authors report on the successful surgical treatment of these 4 patients and the impact of ectopic craniopharyngioma recurrence on survival

We present our technique for extraoperative functional mapping in awake children with supratentorial tumors near eloquent cortex. This technique may help optimize tumor resection and/or the functional outcome, especially when an awake craniotomy is not possible or in the setting of coincident seizures. After subdural electrode implantation, extraoperative functional mapping and seizure focus mapping were performed, followed by staged tumor resection. Gross total resection was achieved in 6 patients and subtotal resection in 2. No complications due to electrode placement or invasive monitoring were observed. Staged resection of pediatric brain tumors near the eloquent cortex appears safe, allows functional mapping in awake patients, and may assist in decisions between maximal tumor resection and optimal functional outcome