✓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 vascula-ture 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.
Martin A. Baggenstos, John A. Butman, Edward H. Oldfield and Russell R. Lonser
Russell R. Lonser, Martin Baggenstos, H. Jeffrey Kim, John A. Butman and Alexander O. Vortmeyer
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.
Consecutive VHL patients with small (≤ 1.5 cm) ELSTs who underwent resection at the National Institutes of Health were included. Clinical, imaging, operative, and pathological findings were analyzed.
Ten consecutive VHL patients (6 male and 4 female) with 10 small ELSTs (≤ 1.5 cm; 9 left, 1 right) were included. Serial imaging captured the development of 6 ELSTs and revealed that they originated within the intraosseous (vestibular aqueduct) portion of the endolymphatic duct/sac system. Imaging just before surgery demonstrated that the epicenters of 9 ELSTs (1 ELST was not visible on preoperative imaging) were in the vestibular aqueduct. Inspection during surgery established that all 10 ELSTs were limited to the intraosseous endolymphatic duct/sac and the immediately surrounding region. Histological analysis confirmed tumor within the intraosseous portion (vestibular aqueduct) of the endolymphatic duct/sac in all 10 patients.
ELSTs originate from endolymphatic epithelium within the vestibular aqueduct. High-resolution imaging through the region of the vestibular aqueduct is essential for diagnosis. Surgical exploration of the endolymphatic duct and sac is required for complete resection.
Ashok R. Asthagiri, Gautam U. Mehta, John A. Butman, Martin Baggenstos, Edward H. Oldfield and Russell R. Lonser
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.
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.
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).
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.
Martin Baggenstos, Emily Chew, John A. Butman, Edward H. Oldfield and Russell R. Lonser
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.