Von Hippel-Lindau disease (VHL) is a hereditary cancer syndrome caused by germline mutations of the VHL tumor suppressor gene. Major progress has been made in the last decade in both clinical and fundamental aspects of VHL. The VHL gene product, pVHL, has major and multiple functions: pVHL regulates not only first angiogenesis but also extracellular matrix formation and the cell cycle. A molecular diagnosis of VHL is now available, leading to a transformation in clinical management of patients and their families. Diagnosis of VHL has to be suspected in patients with a VHL-related tumor without familial history and especially in case of hemangioblastoma or endolymphatic sac tumors. Such patients should be systematically investigated for clinical and molecular evidence of VHL disease. Treatment of symptomatic hemangioblastomas remains mainly neurosurgical, often in emergency, but stereotactic radiosurgery is emerging as an alternative therapeutic procedure. In the future, antiangiogenic drugs could represent a potential medical treatment of CNS hemangioblastomas in view of their highly vascular structure. Lastly, visceral manifestations of VHL disease are also of critical importance and require early detection for effective treatment.

Central nervous system hemangioblastomas, endolymphatic sac tumors, and von Hippel-Lindau disease.

Object. This is a retrospective review of 146 surgically treated benign and malignant peripheral non—neural sheath tumors (PNNSTs). Tumor classifications with patient numbers, locations of benign PNNSTs, and surgical techniques and adjunctive treatments are presented. The results of a literature review regarding tumor frequencies are presented. Methods. One hundred forty-six patients with 111 benign and 35 malignant PNNSTs were treated between 1969 and 1999 at the Louisiana State University Health Sciences Center (LSUHSC). The benign tumors included 33 ganglion cysts, 16 cases of localized hypertrophic neuropathy, 12 lipomas, 12 tumors of vascular origin, and 11 desmoid tumors. There were four each of lipofibrohamartomas, myositis ossificans, osteochondromas, and ganglioneuromas; two each of meningiomas, cystic hygromas, myoblastoma or granular cell tumors, triton tumors, and lymphangiomas; and one epidermoid cyst. The locations of benign PNNSTs were the following: 33 in the brachial plexus region, 39 in ...

A series of 146 peripheral non—neural sheath nerve tumors: 30-year experience at Louisiana State University Health Sciences Center

Haemangioblastomas are rare neoplasms of uncertain histogenesis. They represent 1.5-2.5% of intracranial tumours. While the cerebellum is by far the most frequent site, these lesions also tend to occur in the medulla and spinal cord. Most haemangioblastomas are sporadic but up to one quarter are associated with Von Hippel-Lindau disease (VHL). Although a fairly good number of haemangioblastomas were reported, a lack of side-by-side analysis of these reports has resulted in tentative conclusions that merely offer a first glimpse at their clinicopathologic diversity and histogenesis. To remedy this issue, this study presents a literature review concerning these lesions. Medline literature including both relevant monographs and clinicopathological case series. Haemangioblastomas occur either as a part of VHL disease (25-30%, inherited mutation of VHL gene on 3p25-26 chromosome) or as sporadic tumours (often with somatic mutation of VHL gene). They have diverse clinicopathologic presentations with cerebellar lesions having a better prognosis than their brainstem counterparts. Immunostaining is important for separation of haemangioblastomas from other tumours with similar histology. The rich vascularity of haemangioblastomas is due to overexpression of vascular endothelial growth factors. Moreover, 'stromal' cells represent the neoplastic cells of haemangioblastomas and are capable of forming blood islands with extramedullary haematopoiesis.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2613.2007.00535.x

Central nervous system capillary haemangioblastoma: the pathologist's viewpoint.

Hemangioblastoma is a rare tumor of uncertain histotype that typically arises in the cerebellum, quite often in the setting of Von Hippel-Lindau syndrome (VHL). Exceptional cases of hemangioblastoma arising outside the central nervous system have been reported, but little is known about their clinicopathologic and immunohistochemical features. Twenty-two cases of hemangioblastoma arising at peripheral sites were identified in consultation files. Clinical, morphologic, and immunohistochemical features were evaluated. Outcome data were obtained from referring pathologists. Twelve patients were female and 10 male; the median age was 58 years (range, 27 to 79 y). All the tumors were solitary (except 1) and arose in spinal nerve roots (12), kidney (3), intestine (2), orbit (1), forearm (1), peritoneum (1), periadrenal soft tissue (1), and flank (1). Five patients had VHL; another 5 had lesions suggestive of VHL. One patient had tuberous sclerosis. The median tumor size was 4 cm (range, 1.3 to 15 cm). Most tumors were well circumscribed; 6 were poorly marginated-3 eroded the adjacent bone and 1 extended into the pleura. All tumors were composed of an admixed population of plump spindle cells and microvacuolated cells with palely eosinophilic or clear cytoplasm, which often mimicked lipoblasts or renal cell carcinoma. In 5 cases the microvacuolated cells were scant. Spindle cell nuclei were hyperchromatic or vesicular with inconspicuous nucleoli. Four tumors showed marked nuclear pleomorphism. Mitotic activity was low (range, 0 to 2/10 HPF). All tumors had a complex capillary network, with admixed larger thin-walled or thick-walled vessels in a solid and often lobular growth pattern, similar to central nervous system hemangioblastoma. In 9 cases the larger vessels showed a branching hemangiopericytoma-like pattern. No necrosis or lymphovascular invasion was identified. Tumor cells expressed inhibin in 95% (20/21), neuron-specific enolase in 79% (15/19), and S100 protein in 65% (13/20); they also expressed GLUT1 (7/10, mostly weak), SMA (4/5), epithelial membrane antigen (2/8, focal), PAX8 (1/10), and desmin (1/4). Brachyury was consistently negative (0/19), as were keratin, HMB-45, melan-A, and GFAP. CD31 and CD34 highlighted tumor vasculature. Follow-up information was available for 17 patients (range, 5 to 117 mo; median 36 mo). Three patients had locally persistent disease after incomplete resection. True local recurrence or distant metastasis has not been identified in any patient so far. One patient died of metastatic renal cell carcinoma. Peripheral hemangioblastoma is rare, often associated with VHL syndrome, and may mimic some malignant tumors. The immunohistochemical profile can aid diagnosis. Unresectable cases may be locally aggressive, but complete excision appears to be curative. Recognition of this tumor may identify patients in whom testing for VHL syndrome is warranted.

Peripheral hemangioblastoma: clinicopathologic characterization in a series of 22 cases.

BACKGROUND AND PURPOSE: Hemangioblastomas (HBs) are rare lesions accounting for 1–5% of all spinal cord tumors. Seventy-five percent of spinal HBs are intramedullary. Lesions of the conus medullaris and the cauda equina are uncommon, and the filum terminale location is very rare. HBs of the lower spinal region are highly vascular tumors requiring surgery that is potentially complicated by excessive bleeding. In the literature, there are few reports concerning preoperative embolization of HBs, and only few cases are reported in spinal location. Presurgical embolization of HBs located in the lower spinal region has not been described. Although lower spinal HBs are predominantly fed by the anterior spinal artery (ASA), embolization of these lesions is possible and can reduce tumor vascular supply, thus facilitating surgery. We report our experience in four rare cases of solitary HBs occurring in the lower spinal region. METHODS: Clinical charts and radiologic studies of four patients with a preoperatively embolized HB of the lower spinal region were retrospectively reviewed. The lesions were located in the conus medullaris in one case, at the level of the cauda equina in another, and in the filum terminale in two. In the conus medullaris case, the neoplasm was associated with a syrinx. In three patients, the HB was sporadic, while the patient with the HB of the cauda equina had Von Hippel-Lindau disease. Devascularization of the tumor was performed through the ASA in all cases and also through the posterior spinal artery in one by using non reabsorbable calibrated microspheres in three cases and polyvinyl alcohol particles in the other one. RESULTS: Embolization caused no permanent complications, although one patient with a cauda equina HB mildly worsened after the endovascular procedure but recovered before surgery. At surgery, the tumor was completely removed in all cases. Blood loss was reported to be less than usually observed (100, 200, 200, and 400 mL). In addition, manipulation and removal of the tumor was reported to be easy in three of four tumors. Histologic examination confirmed the diagnosis. At 1-year postsurgical follow-up, two patient recovered completely from neurologic deficits, and two showed significant recovery. No tumor recurred during a follow-up period of 1–6 years (mean, 3.5 years). CONCLUSION: Our results indicate that preoperative embolization of HBs of the lower spinal region is an useful procedure in aiding surgical resection of these highly vascular tumors. With a meticulous technique, embolization can be performed through the ASA.

http://www.ajnr.org/content/ajnr/26/4/936.full.pdf

A. G. Rasmussen

Papers

Peripheral nerve hemangioblastoma