Treatment of von Hippel-Lindau retinal hemangioblastoma by the vascular endothelial growth factor receptor inhibitor SU5416 is more effective for associated macular edema than for hemangioblastomas

Vitrectomy-Assisted Excision in the Treatment of Juxtapapillary Retinal Capillary Hemangioma

Juxtapapillary retinal capillary hemangiomas are sight-threatening hamartomas located on or adjacent to the optic nerve. Nonsurgical approaches including laser photocoagulation and cryotherapy have been shown to be effective to reduce exudation in peripheral hemangiomas. However, in juxtapapillary hemangiomas, the functional outcomes are limited due to associated potential damage of the retinal nerve fiber layer. We present an 18-year-old female patient with von Hippel-Lindau (VHL) disease who presented with a juxtapapillary retinal capillary hemangioma associated with a tractional epiretinal membrane (ERM) and secondary macular hole. After vitrectomy-assisted excision of the lesion and inner limiting membrane (ILM) peeling around the macular hole, visual acuity and macular anatomy were recovered at 10 months of follow-up. [Ophthalmic Surg Lasers Imaging Retina 2022;53:570-573.].

Ophthalmological Aspects of von-Hippel-Lindau Syndrome

Background: von Hippel-Lindau (VHL) syndrome is a multisystem neoplastic disorder involving eyes, central nervous system, kidneys, spine, and other tissues. A retinal capillary hemangioma (RCH) is the earliest manifestation of the VHL disease in most cases.Areas covered:This paper aims to provide an up-to-date review of the current literature about von Hippel-Lindau syndrome. Molecular background, systemic and ocular features of the diseases as well as the utility of newer imaging modalities in diagnosis and monitoring of ocular VHL disease have been described. Besides, we have discussed newer treatment modalities and therapeutic targets.Conclusion: Modern imaging technologies like optical coherence tomography and optical coherence tomography angiography are tools of the trade, in making an appropriate diagnosis and monitoring disease activity and response to treatment. Peripheral RCH may be treated using laser photocoagulation in tumors up to 3000 µm. Vascular endothelial growth factor suppression can help in reducing tumor activity and stabilize the tumor size; however, it does not regress the RCH.

VON HIPPEL-LINDAU DISEASE: Update on Pathogenesis and Systemic Aspects

PURPOSE

To provide an update summarizing the biologic pathways governing von Hippel-Lindau (VHL) disease pathogenesis and to provide an overview of systemic manifestations as well as screening recommendations.

METHODS

A PubMed search of the English language literature was reviewed using the following search terms: von Hippel-Lindau, von Hippel-Lindau disease, and VHL. Of 6,696 publications, the most current and pertinent information related to the pathogenesis and systemic aspects of VHL disease were included in this review.

RESULTS

von Hippel-Lindau disease is one of the most frequently occurring multisystem familial cancer syndromes. The disease results from germline mutation in the VHL tumor suppressor gene on the short arm of chromosome 3. Mutation in the VHL gene affects multiple cellular processes including transcriptional regulation, extracellular matrix formation, apoptosis, and, in particular, the cellular adaptive response to hypoxia. As a result, there is widespread development of vascular tumors affecting the retina, brain, and spine, as well as a spectrum of benign and malignant tumors and/or cysts in visceral organs.

CONCLUSION

The ophthalmologist plays a key role in VHL disease diagnosis, as retinal hemangioblastoma is frequently the first disease manifestation. Screening guidelines for individuals with known VHL disease, and those at risk of VHL disease, help to ensure early detection of potentially vision-threatening and life-threatening disease.

Von Hippel-Lindau Disease: Current Challenges and Future Prospects

Understanding of molecular mechanisms of tumor growth has an increasing impact on the development of diagnostics and targeted therapy of human neoplasia. In this review, we summarize the current knowledge on molecular mechanisms and their clinical implications in von Hippel-Lindau (VHL) disease. This autosomal dominant tumor syndrome usually manifests in young adulthood and predisposes affected patients to the development of benign and malignant tumors of different organ systems mainly including the nervous system and internal organs. A consequent screening and timely preventive treatment of lesions are crucial for patients affected by VHL disease. Surgical indications and treatment have been evaluated and optimized over many years. In the last decade, pharmacological therapies have been evolving, but are largely still at an experimental stage. Effective pharmacological therapy as well as detection of biomarkers is based on the understanding of the molecular basis of disease. The molecular basis of von Hippel-Lindau disease is the loss of function of the VHL protein and subsequent accumulation of hypoxia-inducible factor with downstream effects on cellular metabolism and differentiation. Organs affected by VHL disease may develop frank tumors. More characteristically, however, they reveal multiple separate microscopic foci of neoplastic cell proliferation. The exact mechanisms of tumorigenesis in VHL disease are, however, still not entirely understood and knowledge on biomarkers and targeted therapy is scarce.

Disseminated central nervous system hemangioblastoma in a patient with no clinical or genetic evidence of von Hippel-Lindau disease-a case report and literature review

BACKGROUND

Hemangioblastomas (HB) are benign tumors of the central nervous system (CNS) that can appear sporadic or as part of von Hippel-Lindau (VHL) disease. It is often curable with surgical resection, but upon relapse, the disease exhibits a treatment-refractory course.

CASE REPORT

A patient treated for sporadic cerebellar HB relapsed 12 years post-surgery. She developed disseminated disease throughout the CNS, including leptomeningeal manifestations. Repeat surgery and craniospinal radiation therapy were unsuccessful.

CONCLUSION

This case is in line with previous publications on disseminated non-VHL HB. Available treatment options are inefficient, emphasizing the need for improved understanding of HB biology to identify therapeutic targets.

A novel mutation in the VHL gene in a Chinese family with von Hippel-Lindau disease

BACKGROUND

Von Hippel-Lindau (VHL) disease is an autosomal dominant inherited cancer syndrome, and VHL is identified as a tumor suppressor gene. The main objective of this study was to identify disease-causing mutations in a Chinese family affected with VHL disease.

METHODS

Genomic DNA was extracted from peripheral blood from a Chinese family with VHL. A predicted pathogenic variant was identified by targeted exome capture technology and next-generation sequencing.

RESULTS

A novel heterozygous mutation (c.349 T > A, p.W117R) was detected in affected family members. No mutation was detected in unaffected family members or in the 150 normal controls. The mutation segregated with the disease phenotype throughout three generations. Histopathological examination revealed the characteristics of hemangioblastoma.

CONCLUSIONS

A novel W117R was detected in the VHL gene that caused retinal hemangioblastomas in affected members of a Chinese family.

Effect of intravitreal dexamethasone on macular edema in von Hippel-Lindau disease assessed using swept-source optical coherence tomography: a case report

BACKGROUND

Von Hippel-Lindau disease is a rare hereditary syndrome caused by germinal mutations in a von Hippel-Lindau tumor-suppressing gene. Retinal hemangioblastoma is the ocular hallmark lesion of von Hippel-Lindau disease.

CASE PRESENTATION

A 20-year-old Caucasian woman presented to our institution with painless visual impairment in the right eye. A fundus ophthalmoscopic evaluation and swept-source optical coherence tomographic examination revealed a retinal hemangioblastoma associated with cystoid macular edema. On the basis of the clinical ocular findings and genetic analysis, von Hippel-Lindau disease was diagnosed. Following an intravitreal injection of ranibizumab, off-label administration of intravitreal dexamethasone was considered to reduce the edema. An almost complete resolution of the edema in the macular area was observed 1 week after the injection. Finally, laser photocoagulation and transconjunctival cryotherapy were performed; the patient developed "ablatio fugax" after cryotherapy.

CONCLUSIONS

In our experience, intravitreal dexamethasone administration has proven to be a useful tool for reducing retinal hemangioblastoma-related macular edema in von Hippel-Lindau disease and may be considered a potentially valuable treatment that can be used in combination with other therapies.

The von Hippel–Lindau Tumor Suppressor Protein

The von Hippel–Lindau (VHL) gene is a two-hit tumor suppressor gene and is linked to the development of the most common form of kidney cancer, clear cell renal carcinoma; blood vessel tumors of the retina, cerebellum, and spinal cord called hemangioblastomas; and tumors of the sympathoadrenal nervous system called paragangliomas. The VHL gene product, pVHL, is the substrate recognition subunit of a cullin-dependent ubiquitin ligase that targets the α subunits of hypoxia-inducible factor (HIF) for destruction when oxygen is plentiful. Mounting evidence implicates HIF2 in the pathogenesis of pVHL-defective tumors and has provided a conceptual foundation for the development of drugs to treat them that inhibit HIF2-responsive gene products such as VEGF and, more recently, HIF2 itself. pVHL has additional, noncanonical functions that are cancer relevant, including roles related to the primary cilium, chromosome stability, extracellular matrix formation, and survival signaling.

Sunitinib for the treatment of benign and malignant neoplasms from von Hippel-Lindau disease: A single-arm, prospective phase II clinical study from the PREDIR group

Von Hippel-Lindau (VHL) disease is an autosomal dominant hereditary cancer syndrome that predisposes affected individuals to the development of multiple benign and malignant tumors. One of the main manifestations of VHL is renal cell carcinoma (RCC). RCC is increasingly being treated with targeted therapies, which offer an alternative treatment option for patients with VHL disease. This study investigated the effectiveness of sunitinib in VHL patients with advanced tumors or tumors unsuitable for surgery.This multicenter, phase II, open-label study from the PREDIR VHL network, treated patients with genetically-confirmed advanced VHL disease with oral sunitinib (50 mg/day for 28 days then a 2-week rest period) until progression. Lesions were performed using magnetic resonance imaging (MRI) and computed tomographic (CT) scan. The primary endpoint was objective response rate; secondary endpoints included tolerability and overall survival.All five patients showed stable disease as best response at 6 months. Two patients showed impressive transitory clinical improvement during early cycles. No patient died during sunitinib treatment. Reasons for discontinuing sunitinib therapy were disease progression (n=1), unacceptable toxicity (n=3) and lack of clinical improvement after 7 cycles (10.5 months) with unacceptable toxicity (n=1).In conclusion, sunitinib was of limited benefit in patients with advanced VHL disease, but had better efficacy against metastatic RCC than other VHL-related lesions. Treatment-related toxicity is an important limiting factor in this frail patient population. New agents with different mechanisms of action are required to treat this disease.

Systemic Sunitinib Malate Treatment for Advanced Juxtapapillary Retinal Hemangioblastomas Associated with von Hippel-Lindau Disease

PURPOSE

To describe the clinical course of advanced juxtapapillary retinal capillary hemangioblastomas (RCH) associated with von Hippel-Lindau (VHL) disease treated with systemic sunitinib malate, an agent that inhibits both anti-vascular endothelial growth factor and anti-platelet-derived growth factor signaling.

DESIGN

Observational case review.

PARTICIPANTS

Three patients with advanced VHL-related juxtapapillary RCH treated with systemic sunitinib malate.

METHODS

Patient 1 was followed routinely every 4 months while on systemic sunitinib prescribed by her oncologist for metastatic pancreatic neuroendocrine and kidney tumors. Patients 2 and 3 were part of a prospective clinical trial evaluating the use of systemic sunitinib for ocular VHL lesions during a period of 9 months. Visual acuity, size of RCH, and degree of exudation were recorded at each visit. Optical coherence tomography (OCT) and fluorescein angiography were also obtained at some visits.

MAIN OUTCOME MEASURES

Visual acuity, size of RCH, and degree of exudation.

RESULTS

Three patients with advanced VHL-associated juxtapapillary RCH were treated with systemic sunitinib malate. While none of the patients lost vision during therapy, treatment with sunitinib malate did not improve visual acuity or reduce the size of RCH. Improvements in RCH-associated retinal edema were observed in two patients. All patients experienced multiple adverse effects, including thyroid toxicity, thrombocytopenia, nausea, fatigue, jaundice, and muscle aches. Two of the three patients had to discontinue treatment prematurely and the third required dose reduction.

CONCLUSIONS

Systemic sunitinib malate may be useful in slowing progression of ocular disease from VHL-associated RCH. However, significant systemic adverse effects limited its use in this small series, and systemic sunitinib malate may not be safe for treatment of RCH when used at the doses described in this report. Further studies are required to determine if this medication used at lower doses with different treatment strategies, other medications in the same class or drugs directed at multiple targets in the tumor, may be safer and more effective for the treatment of advanced VHL-associated RCH.

Neurological Management of Von Hippel-Lindau Disease

Von Hippel-Lindau disease is a genetic condition due to mutation of the Von Hippel-Lindau gene, which leads to an increased risk in the development of hemangioblastomas of the brain and spinal cord. The pathophysiology of disease and its clinical manifestations, as they pertain to the general neurologist, are discussed. Therapeutic management of central nervous system hemangioblastomas ranging from neurosurgical resection, radiation therapy, and systemic therapies is reviewed.

An Update on the Ophthalmologic Features in the Phakomatoses

Neurofibromatosis type 1, tuberous sclerosis complex, and Von Hippel-Lindau disease, historically classified as the phakomatoses, are hereditary multisystem disorders characterized by the presence of hamartoma, which carry the risk of malignant transformation. The alteration of tumor suppressor genes seems to be at the basis of their pathophysiogenetic mechanism. Lisch and choroidal nodules in neurofibromatosis type 1, retinal astrocytomas in tuberous sclerosis complex, and retinal capillary hemangioma in Von Hippel-Lindau disease are the principal ophthalmic hamartomatous manifestations. The advent of novel imaging techniques such as near infrared reflectance and optical coherence tomography has provided unprecedented insight on the choroidal and retinal features of these diseases. These methods have improved early diagnosis and the ongoing surveillance in these conditions. Among an array of treatment modalities, antivascular endothelial growth factor therapy has been used in the management of retinal hamartomas but results have been varied. This review is an update on the pathophysiogenetic mechanisms, ophthalmic manifestations, and novel treatment strategies in the phakomatoses with emphasis on the role of imaging techniques.

Activation of hypoxia signaling induces phenotypic transformation of glioma cells: implications for bevacizumab antiangiogenic therapy

Glioblastoma (GBM) is the most common and deadly primary brain tumor in adults. Bevacizumab, a humanized monoclonal antibody against vascular endothelial growth factor (VEGF), can attenuate tumor-associated edema and improve patient symptoms but based on magnetic resonance imaging, is associated with non-enhancing tumor progression and possibly gliosarcoma differentiation. To gain insight into these findings, we investigated the role of hypoxia and epithelial-mesenchymal transition (EMT)-associated proteins in GBM. Tumor markers of hypoxia and EMT were upregulated in bevacizumab-treated tumors from GBM patients compared to untreated counterparts. Exposure of glioma cells to 1% oxygen tension increased cell proliferation, expression of EMT-associated proteins and enhanced cell migration in vitro. These phenotypic changes were significantly attenuated by pharmacologic knockdown of hypoxia-inducible Factor 1α (HIF1α) or HIF2α, indicating that HIFs represent a therapeutic target for mesenchymal GBM cells. These findings provide insights into potential development of novel therapeutic targeting of angiogenesis-specific pathways in GBM.

Intravitreal bevacizumab for retinal capillary hemangioblastoma: A case series and literature review

OBJECTIVE

To evaluate the long-term outcomes of intravitreal bevacizumab for peripheral and juxtapapillary retinal capillary hemangioblastoma (RCH).

DESIGN

We conducted a retrospective noncomparative interventional case series.

PARTICIPANTS

There were 4 patients (5 eyes) presenting with RCH.

METHODS

Five eyes with RCH presented with exudative changes and visual loss. Three eyes of 2 patients with peripheral RCH were treated with cryotherapy and 2 intravitreal injections of bevacizumab (0.5 mg). Two eyes with juxtapapillary RCH were treated with 3 intravitreal injections of bevacizumab. The main outcome measures were changes in best-corrected visual acuity (BCVA), lesion size, exudation, and retinal thickness.

RESULTS

In peripheral RCH, improvement of BCVA from counting fingers to 20/400 was obtained in 1 eye. One patient with bilateral RCH maintained a vision of 20/20 in 1 eye with complete anatomic regression of the 3 small peripheral RCH lesions. The fellow eye with fibrotic bands from the RCH to the optic nerve head developed a tractional retinal detachment after the first injection and was treated with pars plana vitrectomy. In patients with juxtapapillary RCH, bevacizumab injections resulted in an improvement of BCVA from 20/80 to 20/20 in 1 eye, whereas the second eye did not show an improvement of BCVA despite a regression of the tumour.

CONCLUSIONS

Intravitreal anti-vascular endothelial growth factor agents, alone or in combination with other treatment modalities, may improve visual acuity. Further trials evaluating the dose, the number of injections, and the route of administration will be important in advancing antiangiogenic therapies for RCH.

Early-stage hemangioblastoma presenting as a small lesion with significant edema in the cerebellum

Hemangioblastomas are benign tumors that are frequently associated with peritumoral cysts; however, their early characteristics before cyst formation remain unclear. In this article, the authors present a novel case of a cerebellar hemangioblastoma presenting as a small solid lesion with significant edema. Surgery was performed to resect the tumor, and a follow-up magnetic resonance imaging scan revealed complete excision of the mass and resolution of the cerebellar edema. Histological examination confirmed that the lesion was a hemangioblastoma. This is the only report in the literature to describe the imaging and histopathologic characteristics of an initial hemangioblastoma in the cerebellum.

Management of von hippel-lindau disease: an interdisciplinary review

Von Hippel-Lindau (VHL) disease is an autosomal dominantly inherited tumour predisposition syndrome with an incidence of 1:36,000 newborns, the estimated prevalence in Europe is about 1-9/100,000. It is associated with an increased risk of developing various benign and malignant tumours, thus affecting multiple organs at different time points in the life of a patient. Disease severity and diversity as well as age at first symptoms vary considerably, and diagnostic delay due to failure of recognition is a relevant issue. The identification of a disease-causing VHL germline mutation subsequently allows family members at risk to undergo predictive genetic testing after genetic counselling. Clinical management of patients and families should optimally be offered as an interdisciplinary approach. Prophylactic screening programs are a cornerstone of care, and have markedly improved median overall survival of affected patients. The aim of this review is to give an overview of the heterogeneous manifestations of the VHL syndrome and to highlight the diagnostic and therapeutic challenges characteristic for this orphan disease. A comprehensive update of the underlying genetic and molecular principles is additionally provided. We also describe how the St. Gallen VHL multidisciplinary group is organised as an example of interdisciplinary cooperation in a tertiary hospital in Switzerland.

Hemangioblastoma of the optic nerve producing bilateral optic tract edema in a patient with von Hippel-Lindau disease

BACKGROUND

The authors present a novel case of a hemangioblastoma of the optic nerve producing bilateral optic tract edema in a patient with von Hippel-Lindau disease (VHL). This is the only case in the literature documenting optic tract edema secondary to a hemangioblastoma of the optic nerve.

CASE DESCRIPTION

The patient was a 34-year-old female in whom this lesion was causing retro-orbital pain and proptosis. She had previously lost vision in the symptomatic eye secondary to a retinal hemangioblastoma. The optic nerve lesion was excised by sectioning the optic nerve both proximally and distally to the lesion. There were no complications and patient's symptoms resolved postoperatively. A follow-up magnetic resonance imaging (MRI) scan revealed complete excision of the mass and resolution of the optic tract edema.

CONCLUSION

Optic nerve hemangioblastomas in patients with VHL are rare, but are manageable with meticulous microneurosurgery and with appropriate patient expectations. This is the first known case of an optic nerve hemangioblastoma producing bilateral optic tract edema, which resolved after resection of the prechiasmal tumor. Hemangioblastoma should remain in the differential diagnosis of optic nerve tumors, especially in the setting of VHL.

Intravitreal anti-VEGF injection for the treatment of progressive juxtapapillary retinal capillary hemangioma: a case report and mini review of the literature

We report a case of a patient known to have a von Hippel–Lindau disease with documented progressive juxtapapillary retinal capillary hemangioma (JRCH) with well-preserved visual acuity (VA) and visual field (VF). The patient received a single injection of intravitreal ranibizumab (IVR). Six months after IVR injection, the JRCH showed reduced vascularization, fibrosis, and mild shrinkage, and VA and VF remained unchanged. IVR therapy might therefore be considered as an alternative treatment for progressive JRCH, especially in patients with well-preserved VA and VF.

Angiogenesis and hematological malignancies

Since the initial hypotheses on the importance of angiogenesis in the pathogenesis of cancer approximately 30 years ago, there have been major advances in the understanding of the cellular and molecular mechanisms involved in the regulation of this complex process of new vessel formation. Among the multitude of factors, vascular endothelial growth factor (VEGF) has emerged as one of the most potent angiogenic factors, being implicated in the initiation of signal transduction responsible for cell proliferation, survival, migration and adhesion. Inhibition of VEGF and its signaling pathway offers a potential new molecular target in cancer therapy. This article reviews the role of angiogenesis and its mediators, particularly vascular endothelial growth factors, in hematological malignancies, as well as the potential use of anti-angiogenic therapies in the management of these conditions.

Von Hippel-Lindau disease (VHL): a need for a murine model with retinal hemangioblastoma

Von Hippel-Lindau (VHL) disease is a highly penetrant autosomal dominant systemic malignancy that gives rise to cystic and highly vascularized tumors in a constellation of organs. Patients with VHL disease commonly present with hemangioblastomas in the central nervous system and the eye while other manifestations include pheochromocytoma, clear cell renal cell carcinoma, endolymphatic sac tumors of the middle ear, pancreatic cystadenomas, epididymal and broad ligament cystadenomas. Animal models inactivating the VHL gene product in various organ tissues have been constructed over the past 15 years to parse its HIF-associated mechanisms and its link to tumorigenesis. These models, despite advancing our understanding the molecular role of VHL, are by and large unable to recapitulate the more common features of human VHL disease. Up to date, no model exists that develop retinal hemangioblastomas, the most common clinical manifestation. The purpose of this review is: (1) to discuss the need for an ocular VHL model, (2) to review the animal models that recapitulate clinical VHL disease and (3) to propose potential mechanisms of tumorigenesis for the development of ocular VHL.

Von Hippel-Lindau: how a rare disease illuminates cancer biology

Von Hippel-Lindau (VHL) disease is a rare autosomal dominant syndrome (1/36,000 live births) with highly penetrance that predispose to the development of a panel of highly vascularized tumors (model of tumoral angiogenesis). Main manifestations include central nervous system (CNS) and retinal haemangioblastomas, endolymphatic sac tumors, clear-cell renal cell carcinomas (RCC), phaeochromocytomas and pancreatic neuroendocrine tumors. RCC has become the first potential cause of mortality and VHL disease is the main cause of inherited RCC. The disease is caused by germline mutations in the VHL tumor-suppressor gene that plays a major role in regulation of the oxygen-sensing pathway by targeting the hypoxia-inducible factor HIF for degradation in proteasome. VHL has also major HIF-independent functions, specially in regulation of primary cilium, extracellular matrix and apoptosis. Somatic inactivation of the VHL gene is the main molecular event in most sporadic RCC and the treatment of advanced RCC has been revolutionized by targeted therapy with drugs that block angiogenesis. These drugs are now in first line in metastatic sporadic RCC and have shown promising results for RCC, pancreatic neuroendocrine tumors and malignant pheochromocytomas in VHL patients.

Pilot trial of sunitinib therapy in patients with von Hippel-Lindau disease

BACKGROUND

Von Hippel-Lindau (VHL) disease induces vascular neoplasms in multiple organs. We evaluated the safety and efficacy of sunitinib in VHL patients and examined the expression of candidate receptors in archived tissue.

METHODS

Patients with VHL were given four cycles of 50 mg sunitinib daily for 28 days, followed by 14 days off. Primary end point was toxicity. Modified RECIST were used for efficacy assessment. We evaluated 20 archival renal cell carcinomas (RCCs) and 20 hemangioblastomas (HBs) for biomarker expression levels using laser-scanning cytometry (LSC).

RESULTS

Fifteen patients were treated. Grade 3 toxicity included fatigue in five patients. Dose reductions were needed in 10 patients. Eighteen RCC and 21 HB lesions were evaluable. Six of the RCCs (33%) responded partially, versus none of the HBs (P = 0.014). LSC revealed that mean levels of phosphorylated vascular endothelial growth factor receptor-2 were lower in HB than in RCC endothelium (P = 0.003) and mean phosphorylated fibroblast growth factor receptor substrate-2 (pFRS2) levels were higher in HB (P = 0.003).

CONCLUSIONS

Sunitinib treatment in VHL patients showed acceptable toxicity. Significant response was observed in RCC but not in HB. Greater expression of pFRS2 in HB tissue than in RCC raises the hypothesis that treatment with fibroblast growth factor pathway-blocking agents may benefit patients with HB.

von Hippel-Lindau disease: a clinical and scientific review

The autosomal dominantly inherited disorder von Hippel-Lindau disease (VHL) is caused by germline mutations in the VHL tumour suppressor gene (TSG). VHL mutations predispose to the development of a variety of tumours (most commonly retinal and central nervous system haemangioblastomas, clear cell renal carcinoma and phaeochromocytomas). Here, we review the clinical and genetic features of VHL disease, briefly review the molecular pathogenesis and outline clinical management and tumour surveillance strategies.

Vitreoretinal surgery for severe retinal capillary hemangiomas in von hippel-lindau disease

PURPOSE

To evaluate the long-term success rate of vitreoretinal surgery for severe cases of retinal capillary hemangiomas (RCHs) caused by von Hippel-Lindau (VHL) disease.

DESIGN

Retrospective case series.

PARTICIPANTS

Twenty-three eyes of 21 patients with severe exudative or tractional retinal detachment caused by RCH, who had undergone vitreoretinal surgery. Patients' age at initial surgery ranged from 12 to 47 years (median, 27 years), and the fellow eye was already blind in 6 of 21 patients.

INTERVENTIONS

All eyes underwent pars plana vitrectomy with posterior hyaloid detachment epiretinal membrane dissection and silicone oil or gas injection. In 9 eyes, retinectomy was performed to remove the RCH (group R). In the other 14 eyes, the RCH was treated by laser endophotocoagulation alone or combined with transscleral cryotherapy (group L).

MAIN OUTCOME MEASURES

Visual acuity (preoperative, 6 and 18 months postoperatively), rate of RCH recurrence, and postoperative complications.

RESULTS

In group R, an average of 2 operations per patient was needed. Six months after surgery, the retina was flat in 8 eyes. Mean follow-up was 8 years. Long-term complications included RCH reproliferation and neovascular glaucoma in 4 eyes, 4 to 8 years after initial surgery. In the remaining 5 eyes, visual acuity ranged from 20/320 to counting fingers 18 months postoperatively. In group L, an average of 1.7 operations was needed. Six months after surgery, the retina was flat in 13 of 14 eyes. Mean follow-up was 4 years. New RCH occurred in 10 eyes and required laser treatment. In the long term, 1 eye became blind after 5 years because of aggressive RCH reproliferation and neovascular glaucoma, and 2 eyes became blind after 10 years because of exudative retinal detachment. In the 11 remaining eyes, visual acuity ranged from 20/320 to 20/20 (median: 20/50) 18 months postoperatively.

CONCLUSIONS

Vitreoretinal surgery is an effective treatment for severe VHL retinal hemangiomas. Large RCHs were satisfactorily treated by (1) vitrectomy with epiretinal dissection and endolaser photocoagulation or (2) retinectomy for RCH resection, although a high rate of vision-threatening RCH recurrence was observed in the long term. However in most cases, surgery improved or prolonged visual function in these eyes.

Neurosurgical considerations in von Hippel-Lindau disease

Von Hippel-Lindau disease is an inherited syndrome predisposing to a variety of benign and malignant neoplasms of the central nervous system and viscera that requires comprehensive screening and follow-up of individuals and their families. As such, it is important for the neurosurgeon to be aware of its clinical features and management issues. In this article we review the clinical aspects, management and surveillance of von Hippel-Lindau disease for neurosurgical practice.

Indirect laser treatment and anti-VEGF therapy of a retinal angioma, with resolution of a large serous retinal detachment, macular exudates, and macular edema

PURPOSE

To report on a novel treatment strategy in an eye with a retinal angioma and macular edema

METHODS

Wide-angle angiography was used to characterize the lesion and response to theraphy, while the treatment combined laser photocoagulation with the indirect laser delivery system, and intravitreal injections of pegaptanib and bevacizumab. Treatment was rendered over 21 months' time.

RESULTS

The treatment resulted in graduate resolution of marked macular edema and exudation, with a gain in visual acuity.

CONCLUSION

A combination of laser photocoagulation and anti-VEGF theraphy can be effective in the treatment of macular exudation and edema from a retinal angioma.

Erlotinib therapy for central nervous system hemangioblastomatosis associated with von Hippel-Lindau disease: a case report

There is a need for effective systemic therapy for central nervous system (CNS) hemangioblastomas (HBs). We report a case of erlotinib therapy for CNS HBs in a patient with von Hippel-Lindau disease, in whom the HBs were associated with diffuse leptomeningeal seeding. We provide the first report of paired serum and cerebrospinal fluid (CSF) levels of erlotinib while on standard dosing. The patient exhibited neurologic and imaging signs of recurrent CNS HBs and progressive leptomeningeal metastasis following surgery, radiation, and stereotactic radiosurgery. The patient was treated with erlotinib 150 mg daily. The patient achieved a minor response to erlotinib therapy, including clinical improvement, reduction in size of two enhancing brain lesions (one of which, however, proved at autopsy to be radiation necrosis) and stabilization of leptomeningeal enhancement. In addition, the CSF white count improved. The duration of response was 9 months. The median plasma and CSF levels of erlotinib while on treatment were 1146.06 and 247.83 ng/ml, respectively (CSF 21.6% of plasma). Erlotinib may have antitumor activity in CNS HBs.

Monotherapy with thalidomide for treatment of spinal cord hemangioblastomas in a patient with von Hippel-Lindau disease

Von Hippel-Lindau (VHL) disease is a cancer-prone syndrome characterized by abnormalities in vascular proliferation and the development of both the visceral and CNS tumors. Complications from hemangioblastoma are among the principal causes of death from this syndrome. Antiangiogenic therapy has been used with different modalities in patients suffering from such complications. Here, we describe an adolescent with VHL complicated by progressive, multifocal spinal hemangioblastomas. Treatment with single-agent thalidomide over the course of 3 years was associated with an unexpected stabilization of the disease. The antiangiogenic effect of thalidomide may be associated with the control of progressive hemangioblastoma.

Disseminated hemangioblastomatosis of the central nervous system without von Hippel-Lindau disease: a case report

We report a very rare case of hemangioblastomatosis that developed after surgical removal of a solitary cerebellar hemangioblastoma (HB). A 51-yr-old man presented with back pain 10 yr after undergoing surgery for cerebellar HB. Magnetic resonance imaging showed numerous mass lesions along the entire neuraxis accompanied by prominent leptomeningeal enhancement. Genomic DNA analysis showed no mutation in the von Hippel-Lindau (VHL) genes. A surgical specimen obtained from a lesion in the cauda equina showed pathological findings identical to those of the cerebellar HB that had been resected 10 yr earlier. External beam radiation therapy and radiosurgery were subsequently performed; however, the patient succumbed one year after receiving the diagnosis of hemangioblastomatosis. The reduction of tumor cell spillage during surgery and regular long-term follow-up are recommended for patients with HBs.

Retinal Capillary Hemangiomas and von Hippel-Lindau Disease

von Hippel-Lindau disease is a multisystem familial cancer syndrome that commonly manifests in the eye as retinal capillary hemangiomas. As the earliest manifestation of the disease, these benign hamartomas can lead to secondary visual loss. Their typical clinical characteristics can lead to accurate diagnosis and appropriate treatment with either laser photocoagulation or cryotherapy enhancing one's probability of preserving vision before becoming symptomatic. Accurate diagnosis can also lead to surveillance of the various other organ systems involved in the disease such as the CNS, kidneys, adrenal glands and pancreas. This will also enable the clinician to provide genetic counseling for patients regarding the lifelong manifestations of this disease.

Phase I study of SU5416, a small molecule inhibitor of the vascular endothelial growth factor receptor (VEGFR) in refractory pediatric central nervous system tumors

SU5416 is a novel small molecule tyrosine kinase inhibitor of the VEGF receptors 1 and 2. A phase I dose escalation study stratified by concurrent use (stratum II) or absence (stratum I) of enzyme-inducing anticonvulsant drugs was undertaken to estimate the maximum-tolerated dose (MTD) and to describe the toxicity profile of SU5416 in pediatric patients with refractory brain tumors. Dose escalations were conducted independently for stratum I starting at 110 mg/m(2) while stratum II started at 48 mg/m(2). Thirty-three eligible patients were treated on stratum I (n = 23) and stratum II (n = 10). Tumor types included 23 glial tumors, 4 neural tumors, 4 ependymomas, and 2 choroid plexus carcinomas. The MTD in stratum I was initially estimated to be 110 mg/m(2). The protocol was amended to determine the MTD after excluding transient AST elevation. Re-estimation of the MTD began at the 145 mg/m(2) dose level but due to development of SU5416 being stopped by the sponsor, the trial was closed before completion. The most serious drug-related toxicities were grade 3 liver enzyme abnormalities, arthralgia, and hallucinations. The plasma pharmacokinetics of SU5416 was not significantly affected by the concurrent administration of enzyme-inducing anticonvulsant drugs. Mean values of the total body clearance, apparent volume of distribution, and terminal phase half-life of SU5416 for the 19 patients in stratum I were 26.1 +/- 12.5 l/hr/m(2), 41.9 +/- 21.4 l/m(2), and 1.11 +/- 0.41 hr, respectively. The plasma pharmacokinetics of SU5416 in children was similar to previously reported findings in adult cancer patients. Prolonged disease stabilization was observed in 4 of 16 stratum I patients.

Etiology and treatment of macular edema

PURPOSE

To summarize current concepts and recent literature regarding the pathogenesis, clinical substrates, and treatment of macular edema, in light of evolving pharmacologic and surgical approaches to this prevalent cause of vision loss.

DESIGN

Interpretive essay.

METHODS

Review and synthesis of selected recent literature, with interpretation and perspective.

RESULTS

Macular edema occurs in a wide variety of pathologic conditions and represents the final common phenotype of several basic pathophysiologic processes. A variety of pharmacologic agents targeting inflammatory and vasopermeability molecules have been shown to reduce macular edema and improve visual function over the short-term. Vitreous surgery effectively addresses the tractional components of macular edema, where present. Despite recent advances, laser photocoagulation remains the treatment of choice for macular edema associated with nondiffuse patterns of vascular leakage.

CONCLUSIONS

Effective management of macular edema is based on recognizing and addressing the pathogenic factors that are operative in a given disease setting. Although treatment options are expanding with the development of new drugs and surgical procedures, the long-term efficacy and safety of most new approaches have yet to be established in controlled clinical trials.

Neurologic manifestations of von Hippel-Lindau disease

von Hippel-Lindau disease (VHL) is an autosomal-dominant neoplasia syndrome that is the result of a germline mutation of the VHL tumor suppressor gene on the short arm of chromosome 3. Patients with VHL are predisposed to develop lesions of the central nervous system and viscera. Central nervous system lesions include hemangioblastomas (the most common tumor in VHL) and endolymphatic sac tumors (ELSTs). Visceral manifestations include renal carcinomas and cysts, pancreatic neuroendocrine tumors and cysts, pheochromocytomas, and cystadenomas of the reproductive adnexal organs. Despite their benign pathology, hemangioblastomas and ELSTs are a frequent cause of morbidity and mortality in patients with VHL. Recent molecular biologic investigations into these VHL-associated central nervous system lesions provide new insight into their origin and development. Emerging data from serial imaging and clinical surveillance protocols provide insight into the natural history of these lesions. Because of the dissimilar pathobiology and clinical course between hemangioblastomas and ELSTs, the optimal management strategies for these neurologic manifestations of VHL are very different.

Intravitreal ranibizumab therapy for retinal capillary hemangioblastoma related to von Hippel-Lindau disease

PURPOSE

To evaluate the effect of intravitreal ranibizumab on retinal capillary hemangioblastomas (RCHs) associated with von Hippel-Lindau (VHL) disease that are not amenable or responsive to standard therapy.

DESIGN

Prospective, noncomparative, interventional case series.

PARTICIPANTS

Five patients with VHL-associated RCH with exudative changes and visual loss.

METHODS

Monthly intravitreal injections of ranibizumab (0.5 mg) were given over a course of 6 months for a total of 7 injections, with additional injections considered until week 52. The final study visit was designated as 8 weeks after the final study injection.

MAIN OUTCOME MEASURES

The primary outcome was the change in best-corrected visual acuity (BCVA) of >/=15 letters at the final visit compared with baseline. Secondary outcomes included change in lesion size, exudation as assessed clinically and by fluorescein angiography, change in retinal thickness as evaluated by optical coherence tomography, and adverse event assessments.

RESULTS

Patients received an average of 10.0+/-3.1 injections over an average period of 47+/-14 weeks, including follow-up. Mean change in BCVA was a decrease of 9+/-20 letters, with 1 patient gaining >/=15 letters, and 2 patients losing >/=15 letters. Changes in both lesion size and exudation were variable.

CONCLUSIONS

Intravitreal ranibizumab, delivered as monotherapy every 4 weeks, had minimal beneficial effects on most VHL-related RCHs. Possible treatment efficacy was demonstrated in the patient with the smallest lesion with less exudation. Future prospective studies are needed to determine the potential role of an antiangiogenic agent, possibly in combination with other therapies for the treatment of such advanced ocular tumors associated with VHL.

Ocular von Hippel-Lindau disease: clinical update and emerging treatments

PURPOSE OF REVIEW

von Hippel-Lindau disease is an inherited, multisystemic cancer syndrome often involving the retina. This review will provide an update for the clinical characterization and treatment of ocular von Hippel-Lindau disease.

RECENT FINDINGS

A comprehensive and quantitative clinical characterization of ocular von Hippel-Lindau disease has been limited by small patient numbers and nonrepresentative sampling. Recently, a large population of patients with clinically and genetically defined von Hippel-Lindau disease was systemically characterized in a single center, enabling a quantitative evaluation of the ocular involvement of this syndrome. Correlations between the nature of von Hippel-Lindau gene mutations and the ocular phenotype were also examined, providing clues as to how disruptions in von Hippel-Lindau protein function may result in eye disease. This understanding may be relevant to the development of new therapies targeting the molecular biology of von Hippel-Lindau disease, some of which are presently being investigated.

SUMMARY

Quantitative studies enable a full characterization of the impact of von Hippel-Lindau disease on eye health and visual function. Establishing correlations between the genotype of the von Hippel-Lindau mutation and the phenotype of eye disease may inform us as to how ocular von Hippel-Lindau disease arises, and help guide molecular interventions in ocular von Hippel-Lindau disease.

Use of intravitreal bevacizumab in a patient with a Von Hippel-Lindau-associated retinal haemangioblastoma of the optic nerve head: a case report

Introduction

The optimum management of a capillary haemangioblastoma affecting the optic nerve head is not clear. A number of treatment modalities have been used to treat the tumours and their consequences. Ocular haemangioblastomas express high levels of vascular endothelial growth factor and levels have been correlated with tumour growth and activity. Treatment with vascular endothelial growth factor inhibitors would therefore seem a logical approach.

Case presentation

We describe a 23-year-old man with an exophytic capillary haemangioblastoma of the optic nerve head that was treated with intravitreal bevacizumab injections.

Conclusion

Unfortunately, treatment with intravitreal bevacizumab on three occasions had no effect on either tumour size or exudation in this patient.

Angiogenesis and gliomas: current issues and development of surrogate markers

Despite significant improvements, current therapies have yet to cure infiltrative gliomas. Glioma progression is strongly dependent on the development of a new vascular network that occurs primarily by angiogenesis. Hypoxia and genetic anomalies within a glioma trigger the angiogenic switch, thus upregulating angiogenic factors and downregulating antiangiogenic factors. The main factors indicative of angiogenesis are now well known, and more recently, differences based on grade and subtype have been reported. New data also indicate a potential role for postnatal vasculogenesis with bone marrow endothelial progenitors in addition to angiogenesis in tumor vascular development. All of these factors may have therapeutic implications. Antiangiogenic therapies are presently being developed; more than 80 trials are ongoing. Initial results indicate that epidermal growth factor receptor inhibitors, anti-metalloproteases, and thalidomide do not demonstrate strong anti-tumor activity. Thus, antiangiogenic agents combined with conventional therapies and second-generation antiangiogenic drugs for targeting multiple molecular pathways are presently being tested. Clinical experience also demonstrates the failure of conventional imaging to monitor these new approaches accurately. New advances in the design of surrogate markers for angiogenesis have been reported for both magnetic resonance and molecular imaging techniques. This article summarizes the mechanisms of the angiogenic switch based on tumor grade and subtype, reviews completed and ongoing clinical trials, and details the present and the future of surrogate markers for angiogenesis in gliomas.

Angiogenesis and vascular malformations: antiangiogenic drugs for treatment of gastrointestinal bleeding

Treatment of gastrointestinal bleeding in patients with angiodysplasias and Osler's disease (hereditary hemorrhagic teleangiectasia) is clinically challenging. Frequently, vascular malformations occur as multiple disseminated lesions, making local treatment an unfavorable choice or impossible. After local therapy, lesions often recur at other sites of the intestine. However, as there are few therapeutic alternatives, repeated endoscopic coagulations or surgical resections are still performed to prevent recurrent bleeding. Hormonal therapy has been employed for more than 50 years but has recently been shown to be ineffective. Therefore, new therapeutic strategies are required. Understanding of the pathophysiology of angiogenesis and vascular malformations has recently substantially increased. Currently, multiple inhibitors of angiogenesis are under development for treatment of malignant diseases. Experimental and clinical data suggest that antiangiogenic substances, which were originally developed for treatment of malignant diseases, may also represent long-awaited specific drugs for the treatment of vascular malformations. However, antiangiogenics display significantly different actions and side-effects. Although antiangiogenics like thalidomide seem to inhibit gastrointestinal bleeding, other substances like bevacizumab can cause mucosal bleeding. Therefore differential and cautious evaluation of this therapeutic strategy is necessary.