Intraventricular Anaplastic Pleomorphic Xanthoastrocytoma: Very Rare Localization and Early Recurrence of a Rare Tumor.

We report a rare case of an adult, with no previous history of seizures, found to have a large intraventricular Anaplastic Pleomorphic Xanthoastrocytoma (APXA). To the best of our knowledge, this is only the second documented report of an APXA located within the ventricular system in an adult. The tumor was characterized by anaplastic features and necrosis without an elevated mitotic index, and it recurred shortly after a gross total surgical resection.

Upgrade of deep bed filtration with activated carbon dosage for compact micropollutant removal from wastewater in technical scale.

The removal of micropollutants from drinking and wastewater by powdered activated carbon (PAC) adsorption has received considerable attention in research over the past decade with various separation options having been investigated. With Switzerland as the first country in the world having adopted a new legislation, which forces about 100 wastewater treatment plants to be upgraded for the removal of organic micropollutants from municipal wastewater, the topic has reached practical relevance. In this study, the process combination of powdered activated carbon (PAC) adsorption and deep bed filtration (DBF) for advanced municipal wastewater treatment was investigated over an extended period exceeding one year of operation in technical scale. The study aimed to determine optimum process conditions to achieve sufficient micropollutant removal in agreement with the new Swiss Water Ordinance under most economic process design. It was shown that the addition of PAC and Fe(3+) as combined coagulation and flocculation agent improved effluent water quality with respect to dissolved organic pollutants as well as total suspended solids (TSS), turbidity and PO4-P concentration in comparison to a DBF operated without the addition of PAC and Fe(3+). Sufficient micropollutant (MP) removal of around 80% was achieved at PAC dosages of 10 mg/L revealing that PAC retained in the filter bed maintained considerable adsorption capacity. In the investigated process combination the contact reactor serves for adsorption as well as for flocculation and allowed for small hydraulic retention times of minimum 10 min while maintaining sufficient MP removal. The flocculation of two different PAC types was shown to be fully concluded after 10-15 min, which determined the flocculation reactor size while both PAC types proved suitable for the application in combination with DBF and showed no significant differences in MP removal. Finally, the capping of PAC dosage during rain water periods, which resulted in lower dosage concentrations, was efficient in limiting PAC consumption during these events without suffering from negative effects on process performance or effluent quality.

Comparison of two PAC/UF processes for the removal of micropollutants from wastewater treatment plant effluent: process performance and removal efficiency.

Two hybrid membrane processes combining powdered activated carbon (PAC) adsorption with ultrafiltration (UF) were investigated regarding operational performance and efficiency to remove organic micropollutants from municipal wastewater treatment plant effluent. A pressurized PAC/UF (pPAC/UF) and a submerged PAC/UF (sPAK/UF) system were operated continuously over a period of six months. Both UF membrane systems showed good compatibility with the application of PAC showing no abrasion or other negative impacts. The pPAC/UF system reached permeability values up to 290 L/(m² h bar) at high fluxes of 80 L/(m² h) compared to the sPAC/UF with a permeability of up to 200 L/(m² h bar) at fluxes of up to 23 L/(m² h). Surface analysis of both membranes with scanning electron microscopy revealed no membrane deterioration after the six-month period of operation. On the surface of the pressurized membrane the formation of a PAC layer was observed, which may have contributed to the high permeability by forming a protective coating. Five micropollutants, i.e. sulfamethoxazole, carbamazepine, mecoprop, diclofenac and benzotriazole in ambient effluent concentrations were investigated. Both PAC/UF systems removed 60-95% of the selected micropollutants at a dosage of 20 mg PAC/L and 4 mg Fe(3+)/L. However, extreme peak loads of sulfamethoxazole with concentrations of up to 30 µg/L caused a considerable performance decrease for more than a week.

Surgical resection of endolymphatic sac tumors in von Hippel-Lindau disease: findings, results, and indications.

OBJECTIVES/HYPOTHESIS: To define the surgical treatment and outcomes of von Hippel-Lindau (VHL) disease-associated endolymphatic sac tumors (ELSTs), we analyzed consecutive VHL patients who underwent ELST resection. STUDY DESIGN: Retrospective investigation of consecutive VHL patients who underwent resection of ELSTs at a clinical research center between 1999 and 2010. METHODS: Analysis of serial clinical examinations, audiograms, imaging studies, and operative findings were analyzed. RESULTS: Thirty-one consecutive patients with ELSTs (15 males, 16 females) underwent resection of 33 tumors (mean follow-up, 49.9 ± 48.0 months; range, 1.0-116 months). One patient had bilateral ELST resections and one patient underwent reoperation for recurrence. Mean age at surgery was 38.2 ± 10.2 years (range, 12-67 years). Whereas 29 ears (88%) had direct radiographic evidence of an ELST, four ears (12%) did not. Mean tumor size was 1.3 ± 1.1 cm (range, 0.2-5.2 cm). Whereas two patients (two ears, 6%) were asymptomatic, 29 patients (31 ears, 94% of ears) had associated audiovestibular symptoms, including sensorineural hearing loss (28 ears, 84%), tinnitus (24 ears,73%), and vertigo (21 patients, 68%). Postoperatively, hearing was stabilized (27) or improved (three) in 97% of 31 ears. Complete tumor resection was achieved in 30 ears (91% of 33 ears). Complications included cerebrospinal fluid leak in two ears (6%) and transient lower cranial nerve palsy in one ear (3%). CONCLUSIONS: Surgical resection of ELSTs can be performed with hearing preservation and a reduction in audiovestibular dysfunction. Early surgical resection can prevent or decrease disabling audiovestibular symptoms, enhance the opportunity for complete resection, and preserve hearing.

Long-term stability after multilevel cervical laminectomy for spinal cord tumor resection in von Hippel-Lindau disease.

OBJECT: Despite the frequent multiplicity and development of new spinal cord hemangioblastomas that require multiple resections in patients with von Hippel-Lindau (VHL) disease, the long-term effects of spinal surgery on spinal column stability in this neoplasia disorder are not known. To determine the effect of multilevel cervical laminectomy for spinal cord tumor resection in VHL, the authors analyzed long-term clinical and radiographic outcomes. METHODS: The authors included consecutive patients enrolled in a prospective VHL disease natural history study who underwent cervical laminectomy(s) for spinal cord hemangioblastoma resection. Serial clinical examinations, neck disability indices, and radiographs (static and dynamic), as well as operative records, were analyzed. RESULTS: Twenty-five adult patients (16 female, 9 male) with VHL disease underwent 34 operations (mean 1.4 ± 0.7 [± SD]/patient) for the resection of cervical spinal cord hemangioblastomas (mean number of lamina removed/surgery 3.0 ± 1.3). The mean age at surgery was 33.9 ± 11.9 years (range 18-61 years), and the mean follow-up duration was 9.1 ± 5.6 years. At last follow-up, radiographic criteria indicated that 9 patients (36%) had spinal column instability, 13 patients (52%) developed a cervical spinal deformity, 4 patients (16%) developed moderate to severe neck disability, and 3 patients (12%) met the criteria for clinical instability. Removal of the C-2 lamina was associated with the development of clinical instability (p = 0.02, Fisher exact test); older age at surgery was associated with the development of cervical deformity (p = 0.05, logistic regression); and a greater number of operations (suboccipital-T4) were associated with increased neck disability indices (p = 0.01, linear regression). CONCLUSIONS: Whereas patients with VHL disease will often require multiple laminectomies for cervical spinal cord hemangioblastoma resection, a limited number of patients (12%) will develop clinical instability. Because prophylactic cervical instrumentation confers limited benefit at the time of spinal cord tumor resection for most patients, and because these patients need life-long MR imaging of the spinal cord, the quality of which may be affected by instrumentation, longitudinal clinical and radiological evaluation may be used to determine which patients will require stabilization.

Progressive peritumoral edema defining the optic fibers and resulting in reversible visual loss.

Hemangioblastomas are frequently associated with peritumoral edema caused by extravasation of plasma ultrafiltrate through permeable neoplastic vessels. The authors report the clinical and imaging findings in a 62-year-old man with von Hippel-Lindau disease who presented with rapid (within 24 hours) loss of color vision and nearcomplete loss of left eye vision (acuity too poor to test). Serial MR imaging demonstrated a stable vascular tumor in the medioinferior aspect of the left optic nerve, associated with progressive edema extending from the nerve through to the bilateral optic radiations. Complete resection of the lesion was performed via an extended transsphenoidal approach, and histological examination confirmed the lesion was a hemangioblastoma. Postoperatively, the patient recovered color vision and had improvement in visual acuity (20/320). Serial imaging in this unique case captured the progressive extravasation of peritumoral edema that tracked and defined the parallel white matter tracts of first- and second-order neurons of the optic system, causing vision loss. Tumor resection led to resolution of the edema and improvement in visual function.

The vestibular aqueduct: site of origin of endolymphatic sac tumors.

OBJECT: Although endolymphatic sac tumors (ELSTs) frequently destroy the posterior petrous bone and cause hearing loss, the anatomical origin of these neoplasms is unknown. To determine the precise topographic origin of ELSTs, the authors analyzed the imaging, operative, and pathological findings in patients with von Hippel-Lindau disease (VHL) and ELSTs. METHODS: Consecutive VHL patients with small (

Mechanisms of morbid hearing loss associated with tumors of the endolymphatic sac in von Hippel-Lindau disease.

CONTEXT: Endolymphatic sac tumors (ELSTs) are associated with von Hippel-Lindau disease and cause irreversible sensorineural hearing loss (SNHL) and vestibulopathy. The underlying mechanisms of audiovestibular morbidity remain unclear and optimal timing of treatment is not known. OBJECTIVE: To define the mechanisms underlying audiovestibular pathophysiology associated with ELSTs. DESIGN, SETTING, AND PATIENTS: Prospective and serial evaluation of patients with von Hippel-Lindau disease and ELSTs at the National Institutes of Health between May 1990 and December 2006. MAIN OUTCOME MEASURES: Clinical findings and audiologic data were correlated with serial magnetic resonance imaging and computed tomography imaging studies to determine mechanisms underlying audiovestibular dysfunction. RESULTS: Thirty-five patients with von Hippel-Lindau disease and ELSTs in 38 ears (3 bilateral ELSTs) were identified. Tumor invasion of the otic capsule was associated with larger tumors (P = .01) and occurred in 7 ears (18%) causing SNHL (100%). No evidence of otic capsule invasion was present in the remaining 31 ears (82%). SNHL developed in 27 of these 31 ears (87%) either suddenly (14 ears; 52%) or gradually (13 ears; 48%) and 4 ears had normal hearing. Intralabyrinthine hemorrhage was found in 11 of 14 ears with sudden SNHL (79%; P < .001) but occurred in none of the 17 ears with gradual SNHL or normal hearing. Tumor size was not related to SNHL (P = .23) or vestibulopathy (P = .83). CONCLUSIONS: ELST-associated SNHL and vestibulopathy may occur suddenly due to tumor-associated intralabyrinthine hemorrhage, or insidiously, consistent with endolymphatic hydrops. Both of these pathophysiologic mechanisms occur with small tumors that are not associated with otic capsule invasion.

Role of edema in peritumoral cyst formation.

Peritumoral cysts (those arising immediately adjacent to the tumor mass) are frequently associated with benign and malignant tumors of the brain and spinal cord (syringomyelia). The cystic component of central nervous system (CNS) tumors and associated peritumoral cysts are often the cause of clinical symptoms. Because of the common occurrence of peritumoral cysts with CNS neoplasms and the morbidity associated with them, advanced imaging, histological, and molecular techniques have been used to determine the mechanism underlying cyst formation and propagation. Based on evidence from such studies, edema appears to be a common precursor to peritumoral cyst formation in the CNS. Mediators of vascular permeability acting locally in the tumor and/or hydrodynamic forces within abnormal tumor vasculature appear to drive fluid extravasation. When these forces overcome the ability of surrounding tissue to resorb fluid, edema and subsequent cyst formation occur. These findings support the concept that the tumor itself is the source of the edema that precedes cyst formation and that resection of tumors or medical therapies directed at decreasing their vascular permeability will result in the resolution of edema and cysts.

Multiple metachronous brain metastases from primary ureteral carcinoma.

Transitional cell carcinoma (TCC) of the ureter is an uncommon urologic malignancy, with approximately 150 cases diagnosed annually. Metastatic brain disease from ureteral TCC is exceedingly rare. To our knowledge, our case report represents only the second report of brain metastasis from ureteral TCC and the only reported patient to undergo resection of their TCC brain metastasis.