VHL gene deletion and enhanced VEGF gene expression detected in the stromal cells of retinal angioma

Novel Surgical Treatment of an Intraretinal Juxtapapillary Hemangioblastoma Using Intraocular Diathermy Forceps: A Case Report

The surgical treatment of intraretinal juxtapapillary retinal hemangioblastomas (JRHs) was previously contraindicated because of the significant risk of collateral damage to the macula and optic nerve. This case report discusses the effectiveness and safety of a novel surgical technique using intraocular bipolar diathermy forceps to coagulate feeder and draining blood vessels of an intraretinal JRH. The patient suffered from bilateral retinal hemangioblastomas with loss of visual function in one eye and the development of an intraretinal JRH in the other eye. Despite intensive treatment with intravitreal bevacizumab and subconjunctival triamcinolone acetonide, growth of the intraretinal JRH continued, macular exudation worsened, and visual acuity decreased. Surgical treatment was undertaken in which, first, the feeder and draining vessels of the JRH were identified by comparing the retinal imaging of the JRH with the imaging before the emergence of the JRH 4 years earlier. Then, retinal incisions were made above the blood vessels and parallel to the nerve fibers during a pars plana vitrectomy. Lastly, these vessels were lifted above the retinal surface and coagulated using intraocular diathermy forceps. Postoperatively, macular edema reduced, and visual acuity increased and remained stable for about 6 months. Using intraocular diathermy forceps, this case report demonstrates effective and safe intraretinal JRH blood vessel coagulation above the retinal surface. This novel surgical approach was able to delay the deterioration of visual acuity due to tumor growth and exudation in this patient. This suggests that coagulation with intraocular diathermy forceps can be considered an additional surgical treatment option for JRHs, especially those with an intraretinal growth pattern.

Hyper-reflective retinal foci as possible in vivo imaging biomarker of microglia activation in von Hippel-Lindau disease

Purpose

von Hippel-Lindau (VHL) disease is caused by a mutation of the VHL gene and characterized by the development of retinal hemangioblastomas (RH). Current pathophysiologic mechanisms of RH development and progression are still insufficient to predict RH behavior. VHL gene is involved in the cellular response to hypoxia and in many intracellular signaling pathways expressed both in angiogenesis and inflammation. Optical coherence tomography (OCT) allows to identify hyper-reflective retinal foci (HRF) known as aggregates of activated microglial cells as possible in vivo biomarker of local inflammation. The aim of the present study was to investigate the presence of HRF in patients with genetically confirmed VHL disease.

Methods

In this cross-sectional study, patients with VHL underwent complete ophthalmological examination and OCT with HRA + OCT Spectralis. HRF were manually identified and calculated in inner (IR), outer (OR) and full retina. Age-matched healthy subjects were enrolled as controls.

Results

113 eyes of 63 VHL patients and 56 eyes of 28 healthy subjects were evaluated. HRF number was significantly higher in VHL than in controls in IR (28.06 ± 7.50 vs 25.25 ± 6.64, p = 0.042). No difference was observed in OR and in full retina (OR: 7.73 ± 2.59 vs 7.95 ± 2.51, p = 0.599; full retina: 35.79 ± 8.77 vs 33.20 ± 7.47, p = 0.093).

Conclusion

The increase of HRF, which mirror retinal microglial activation, characterizes VHL eyes. The role of activated microglia in the retina of VHL eyes needs to be better investigated, mainly considering local VHL disease manifestations.

Combined therapy guided by multimodal imaging of fifteen retinal capillary hemangioblastomas in a monocular Von Hippel- Lindau syndrome case report

Background

To report the multimodal imaging and treatment of fifteen retinal capillary hemangioblastomas (RCHs) associated with Von Hippel-Lindau syndrome in a monocular patient during a long-term following-up, which supply high-resolution exquisite SS-OCTA images (VG200; SVision Imaging, Ltd., Luoyang, China) and management experience about multiple RCHs.

Case presentation

A 34-year-old monocular male patient complained decreased visual acuity (20/100) without pain and redness in the left eye five years ago. Von Hippel-Lindau syndrome were diagnosed with genetic testing. He, his son and daughter all carried a heterozygosity missense variant c.499C > T (p. Arg167Trp) in the Hg19 gene, a VHL gene located in Chr3:10,191,506. Fifteen RCHs were identified by the application of multimodal imaging, which including fundus photo, fundus autofluorescence (FAF), B-scan ultrasonography (US), fluorescein fundus angiography (FFA), indocyanine green angiography (ICGA) and swept-source optical coherence tomography angiography (SS-OCTA). Transscleral cryotherapy and laser photocoagulation were performed to destroy the largest RCH with the size of 4 PD in diameter. Laser photocoagulation was conducted to seal the middle or tiny RCHs (< 1.5 PD) and their nourishing vessels. The retinal edema and exudative macular detachment were successfully relieved by intraocular injection of bevacizumab for 5 times. The RCHs in the left eye responded well to these treatments and best corrected visual acuity was 20/25 for three years. Three-month recall visits were recommended for him.

Conclusion

For multiple retinal capillary hemangioblastomas in monocular patients, precise combined therapy guided by multimodal imaging has a profound impact on the management of new and recurrent RCHs.

MASSIVE RETINAL NEOVASCULARIZATION IN VON HIPPEL-LINDAU DISEASE: ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR, VITRECTOMY, IMMUNOHISTOCHEMISTRY, AND OPTICAL COHERENCE TOMOGRAPHY FEATURES

PURPOSE

To report a rare presentation of ocular von Hippel-Lindau disease associated with a massive epiretinal vascular proliferation over the macula removed by vitrectomy and submitted to histological analysis.

METHODS

Interventional case report.

RESULTS

A 13-year-old woman with von Hippel-Lindau disease reported progressive visual loss in the right eye over the preceding 6 months. Best-corrected visual acuity was 20/100 in the right eye. Fundoscopy showed retinal neovascularization (RNV) with macular traction and a small superotemporal hemangioblastoma. Spectral-domain optical coherence tomography confirmed increased macular thickness and macular traction secondary to RNV. Bevacizumab was injected intravitreally, resulting in partial regression of RNV. Five days after the injection, the patient underwent complete removal of fibrovascular proliferation via pars plana vitrectomy, followed by peripheral tumor photocoagulation. The specimen was subjected to histopathological and immunohistochemical analyses. At 2 years of follow-up, vision had improved to 20/30, and anatomical improvement was confirmed on both fundoscopy and spectral-domain optical coherence tomography.

CONCLUSION

Ocular von Hippel-Lindau disease may be associated with RNV and macular traction. In such cases, RNV is likely responsive to anti-vascular endothelial growth factor and may be removed surgically along a cleavage plane between the tissue proliferation and the inner retina. In the reported case, the procedure was found to be safe and associated with macular anatomical improvement and vision recovery.

Retinal Glial Cells in Von Hippel-Lindau Disease: A Novel Approach in the Pathophysiology of Retinal Hemangioblastoma

Simple Summary

The in vivo optical coherence tomography analysis of the biomarkers of retinal microglia and macroglia in Von Hippel–Lindau disease represents an innovative field of research. The different behavior of these glial cells in Von Hippel–Lindau patients provides new data regarding the pathophysiology of retinal hemangioblastoma, the most common ocular manifestation of this hereditary disorder. Moreover, these biomarkers show a different behavior in Von Hippel–Lindau patients in relation to the presence or absence of retinal hemangioblastoma. Therefore, we can hypothesize that retinal hemangioblastoma is mainly due to the activation of macroglia by previously activated microglial cells.

Abstract

Background: Von Hippel–Lindau (VHL) disease is a neoplastic syndrome caused by a mutation of the VHL tumor suppressor gene. Retinal hemangioblastoma (RH) is a vascularized tumor and represents the most common ocular manifestation of this disease. At the retinal level, VHL protein is able to regulate tumor growth, angiogenic factors, and neuroinflammation, probably stimulating retinal glial cells. The aim of the present study was to analyze in vivo the optical coherence tomography (OCT) biomarkers of retinal macroglia and microglia in a cohort of VHL patients. Methods: The mean thicknesses of macular retinal nerve fiber layer (mRNFL), ganglion cell layer (GCL), and peripapillary retinal nerve fiber layer (pRNFL) were measured with OCT as biomarkers of retinal macroglia. OCT images were also analyzed to detect and quantify hyperreflective retinal foci (HRF), a biomarker of retinal activated microglia. Results: 61 eyes of 61 VHL patients (22 eyes (36.07%) with peripheral RH and 39 eyes (63.93%) without RH) and 28 eyes of 28 controls were evaluated. pRNFL was thinner in VHL patients (p < 0.05) and in VHL without RH (p < 0.01) compared to controls, and thicker in VHL patients with RH than in those without RH (p < 0.05). The thickness of mRNFL (p < 0.0001) and GCL (p < 0.05) was reduced in VHL patients and in VHL without RH compared to controls, whereas mRNFL (p < 0.0001) and GCL (p < 0.05) were increased in VHL patients with RH compared to those without RH. HRF were significantly higher in number in VHL patients and in VHL without RH, than in controls, and significantly lower (p < 0.05) in the eyes of VHL patients with RH, than in those without RH. Conclusions: The OCT analysis, which detects and allows to quantify the biomarkers of retinal microglia (HRF) and macroglia (pRNFL, mRNFL and GCL), showed a different behavior of these two retinal glial cells populations in VHL patients, related to the presence or absence of peripheral RH. These data allow to hypothesize a novel pathophysiologic pathway of retinal hemangioblastoma in VHL disease.

Intravitreous treatment of severe ocular von Hippel-Lindau disease using a combination of the VEGF inhibitor, ranibizumab and PDGF inhibitor, E10030: Results from a phase 1/2 clinical trial

BACKGROUND

Treatment options for severe ocular von Hippel-Lindau (VHL) disease are limited. This trial evaluated preliminary safety and potential efficacy of combination intravitreous injection with ranibizumab, a vascular endothelial growth factor (VEGF) inhibitor, and E10030, a PDGF inhibitor, for eyes with VHL disease-associated retinal hemangioblastoma (RH) not amenable or responsive to thermal laser photocoagulation.

METHODS

This was a prospective, single-arm, open-label phase 1/2 study, comprised of three adults with VHL-associated RH and vision loss. Intravitreous injections of ranibizumab (0.5 mg) and E10030 (1.5 mg) were given unilaterally every 4 weeks in the study eye through 16 weeks, then every 8 weeks through 48 weeks. Supplementary standard care therapies were allowed without restriction after 40 weeks. The primary outcome was the ocular and systemic adverse effect profile at 52 weeks. Secondary outcomes included changes in best-corrected visual acuity (BCVA), RH size, exudation, epiretinal proliferation and retinal traction, and need for ablative treatment of RH or ocular surgery at week 52.

RESULTS

Three participants each received nine injections prior to week 52 and were followed for 104 weeks. One participant manifested mild episodic ocular hypertension in the study eye. Change in BCVA in the study eye at week 52 for the three participants was -5, -12 and +2 letters. No reduction in RH size was measured at 52 weeks. Variable mild improvements in exudation in two participants at week 16 were not sustained through week 52.

CONCLUSIONS

Combination intravitreous injection with ranibizumab and E10030 demonstrated a reasonable preliminary safety profile, but limited treatment effect.

SEGMENTAL DIFFUSE VASCULAR LEAKAGE: A FLUORESCEIN ANGIOGRAPHIC FINDING IN PATIENTS WITH VON HIPPEL-LINDAU DISEASE

PURPOSE

To describe a novel fluorescein angiographic finding in patients with von Hippel-Lindau disease.

METHODS

Retrospective case series of patients diagnosed with retinal capillary hemangioblastoma (RCH) in the setting of von Hippel-Lindau.

RESULTS

We identified six eyes of three patients with von Hippel-Lindau and leaky retinal vessels. All eyes showed segmental diffuse vascular leakage (SDVL) that was seen in the late phase of the angiogram and that originated from third order and more peripheral retinal veins and adjacent capillaries. These vessels did not drain from the RCHs. Segmental diffuse vascular leakage was mainly seen in the mid and far periphery. In some cases, it was located near the RCHs, while in other cases, it was remote. Segmental diffuse vascular leakage was also seen in one eye without RCHs. On follow-up, the extent and intensity of segmental diffuse vascular leakage did not change after the RCHs were treated with laser or cryotherapy.

CONCLUSION

Diffuse vascular leakage from retinal venules around and away from RCHs in patients with von Hippel-Lindau disease is seen, but the clinical and prognostic importance of this finding is uncertain.

Retinal hemangioblastoma vascular detail elucidated on swept source optical coherence tomography angiography

Purpose

To report the distinct vascular pattern of a treatment-naïve retinal hemangioblastoma imaged on swept source optical coherence tomography angiography (SS-OCTA).

Observations

A 33-year-old female with a history of Von Hippel-Lindau disease presented for follow-up of bilateral retinal hemangioblastomas. Ultra-widefield fundus photography of the left eye revealed a small, juxtapapillary lesion. SS-OCTA imaging centered at the lesion identified two distinct vascular foci. Centrally, the lesion was composed of a dense capillary meshwork. Peripherally, a pattern of branching vessels with terminal budding was identified. The patient was diagnosed with a new juxtapapillary retinal hemangioblastoma.

Conclusions and Importance

SS-OCTA can visualize the in-vivo vascular structure of retinal hemangioblastomas. Early lesion identification can help in prompt diagnosis and monitoring. Further investigation is needed to assert if the branching and budding pattern described in this case report is broadly characteristic of this tumor entity.

Laser speckle flowgraphy in juxtapapillary retinal capillary hemangioblastoma: a case report on natural course and therapeutic effect

Juxtapapillary retinal capillary hemangioblastoma (JRCH), a benign intraocular vascular tumor, is usually progressive and may lead to severe vision loss due to various complications. We herein present a case of JRCH observed with laser speckle flowgraphy (LSFG) before and after laser photocoagulation (LPC). A 21-year-old Japanese woman underwent LSFG evaluations. Right eye showed an orange-colored tumor consistent with JRCH on the papillomacular bundle, where LSFG showed a mild warm-color blood flow signal. Eight months after the first examination, JRCH in the right eye increased redness with vasodilatation, and the size enlarged, where LSFG showed a stronger warm-color blood flow signal. She underwent direct yellow laser ablation for the JRCH lesion. One week after LPC, JRCH became paler and LSFG eventually depicted a weakened blood flow signal at the same site. In conclusion, non-invasive and reproducible LSFG is a useful tool for assessing not only JRCH activity but also therapeutic effect.

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.

Retinal haemangioblastoma associated with peripheral non-perfusion: widefield fluorescein angiography analysis of 41 cases

AIMS

To investigate the association of peripheral retinal non-perfusion with retinal haemangioblastoma.

METHODS

Medical and widefield fluorescein angiography records of patients diagnosed with retinal haemangioblastoma from 1990 to 2018 were reviewed for patient demographics, tumour features, fluorescein angiography features and characteristics of peripheral retinal non-perfusion.

RESULTS

There were 41 eyes of 40 patients with retinal haemangioblastoma imaged by widefield fluorescein angiography during this time period. Of 41 eyes, 14 (34%) had haemangioblastoma-associated peripheral retinal non-perfusion on fluorescein angiography. A comparison of eyes with versus without non-perfusion revealed younger mean age at presentation (28 vs 43 years old, p=0.05), increased prevalence of von Hippel-Lindau (VHL) disease (62% vs 22%, p=0.01), greater mean largest tumour basal diameter (3.7 vs 2.5 mm, p=0.04), greater tumour distance from optic nerve (8.4 vs 1.9 mm, p<0.01) and increased prevalence of vascular leakage from the tumour (86% vs 52%, p=0.03). After mean follow-up of 97 versus 71 months (p=0.52), eyes with non-perfusion were significantly more likely to develop neovascularisation (40% vs 0%, p<0.01) and experience a three-line or greater decrease in visual acuity (60% vs 11%, p<0.01).

CONCLUSION

Peripheral retinal non-perfusion can be associated with retinal haemangioblastoma, and could be more common with larger, more peripheral tumours in younger patients with VHL disease. Eyes with haemangioblastoma-associated peripheral non-perfusion could be more likely to develop neovascularisation and lose visual acuity.

Spontaneous Hyaloidal Contraction and Complex Retinal Detachment in a Patient With Von Hippel-Lindau Syndrome

The authors present an interventional case report of a patient with von Hippel-Lindau (VHL) syndrome who developed simultaneous exudative and combined tractional, rhegmatogenous, and exudative retinal detachment (RD) in the right and left eyes, respectively, following uneventful cryotherapy application of retinal capillary hemangioblastoma (RCH). After pars plana vitrectomy combined with encircling scleral buckling with radial element placement and silicone oil injection, complete retinal reattachment was achieved. The exudative RD of the fellow eye was managed initially with intense topical corticosteroid treatment and subsequent placement of a radial scleral buckle due to the presence of clinically apparent traction. Both eyes remained stable after successful surgical interventions, and long-term follow-up revealed no evidence of recurrent disease. The authors conclude that rapid worsening of vitreoretinal traction and exudation are complications that can occur after treatment of RCH in patients with VHL syndrome leading to complex retinal detachments. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:238-241.].

Peripheral retinal nonperfusion using widefield imaging with von Hippel-Lindau disease

Background

To describe a case of von Hippel-Lindau disease with peripheral retinal nonperfusion.

Case presentation

A 66-year-old female with known cerebellar and midbrain hemangioblastomas was evaluated for a retinal hemangioblastoma in the right eye. She underwent widefield fluorescein angiography, which showed hyperfluorescence localized to the hemangioblastoma surrounded by peripheral retinal nonperfusion in the same quadrant.

Conclusions

Further widefield imaging studies are required to determine if peripheral retinal nonperfusion is a common finding in von Hippel-Lindau disease.

Mutation in the intracellular chloride channel CLCC1 associated with autosomal recessive retinitis pigmentosa

We identified a homozygous missense alteration (c.75C>A, p.D25E) in CLCC1, encoding a presumptive intracellular chloride channel highly expressed in the retina, associated with autosomal recessive retinitis pigmentosa (arRP) in eight consanguineous families of Pakistani descent. The p.D25E alteration decreased CLCC1 channel function accompanied by accumulation of mutant protein in granules within the ER lumen, while siRNA knockdown of CLCC1 mRNA induced apoptosis in cultured ARPE-19 cells. TALEN KO in zebrafish was lethal 11 days post fertilization. The depressed electroretinogram (ERG) cone response and cone spectral sensitivity of 5 dpf KO zebrafish and reduced eye size, retinal thickness, and expression of rod and cone opsins could be rescued by injection of wild type CLCC1 mRNA. Clcc1+/- KO mice showed decreased ERGs and photoreceptor number. Together these results strongly suggest that intracellular chloride transport by CLCC1 is a critical process in maintaining retinal integrity, and CLCC1 is crucial for survival and function of retinal cells.

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.

The American Society of Retina Specialists 2016 Founders Award Lecture

Purpose:

To review the current state of the art of retinal tumors with respect to clinical features, imaging, and management.

Methods:

Review of published literature and personal experience from an ocular oncology service.

Results:

There are several tumors that arise from the sensory retina including those of glial origin (astrocytic hamartoma, acquired astrocytoma, and solitary circumscribed retinal astrocytic proliferation), neural origin (retinoblastoma), and vascular origin (hemangioblastoma, cavernous hemangioma, racemose hemangioma, and vasoproliferative tumor). Most retinal tumors are benign with the exception of retinoblastoma and retinal metastasis. Some retinal tumors are associated with systemic oculoneurocutaneous syndromes such as tuberous sclerosis complex (TSC), 13q deletion syndrome, Von Hippel–Lindau disease, and systemic cavernous and racemose hemangioma syndromes with ocular, cutaneous, neurologic, and other findings. Regarding management, recent data indicate that retinal astrocytic hamartoma and retinal achromic patch are key to the diagnosis of TSC and imply greater risk for brain and kidney tumors. Some children with TSC respond to mammalian target of rapamycin inhibitors, controlling brain, kidney, and eye tumors. Children with retinoblastoma are all screened genetically, and systemic evaluation is provided for detection of metastasis and secondary-related tumors. Newer chemotherapy regimens by intravenous or intra-arterial routes have revolutionized retinoblastoma control. Retinal vascular tumors are uncommon but can have serious systemic implications. Therefore, imaging of the brain for related cerebellar hemangioblastoma, midbrain racemose hemangioma, or multifocal cavernomas is performed. Genetic testing for each disease can be revealing.

Conclusions:

Retinal tumors are often benign, can be recognized by clinical and imaging features, and can be associated with important systemic syndromes.

The Effect of Von Hippel-Lindau Gene Transfer on Human Vascular Smooth Muscle Cell Proliferation and Apoptosis

Von Hippel-Lindau ( VHL) gene is a tumor suppressor gene that plays a genome “gatekeeper” role and controls several downstream effector genes. We have previously demonstrated that both in vivo and in vitro adenovirus-mediated gene transfer of tumor suppressor genes into the vascular endothelium is effective in decreasing neointimal hyperplasia and abnormal cell proliferation. The degree of apoptosis induced by these genes is critical in mediating the in vivo responses to gene therapy and the maintenance of the crucial balance between cell death and viability. Since VHL gene is known to regulate vascular endothelial growth factor (VEGF) as well as other angiogenic factors, it may exhibit a greater potential in the attenuation of vascular disorders in comparison to other tumor suppressor genes. This study focused on whether adenovirus-mediated VHL gene transfer into human vascular smooth muscle cells has an effect on cell proliferation and induction of apoptosis. Human aortic smooth muscle cells (HASMC) were grown as monolayers and transfected with varying titers of adenovirus containing the VHL cDNA (AdVHL). The negative controls were adenovirus containing green fluorescent protein (AdGFP), vector alone (AdNull), and virus-free infection medium. Adenovirus encoding wild-type p53 (Adp53) was used as positive control. Cell viability and proliferation were determined by using trypan blue exclusion and MTS-based CellTiter 96 AQ Proliferation Assay. Apoptosis was evaluated by TUNEL assay, morphologic changes, and nucleosomal DNA degradation. Following AdVHL transfection HASMCs demonstrated a dose-dependent decrease in viability as compared to negative controls (p<0.05). AdVHL-transfected cells exhibited a decrease in their proliferative ability by 40.21 ±1.66 (SEM)%. In cultures transfected with the positive control, Adp53, the cell viability as well as proliferation was highly reduced (p<0.001). AdGFP and AdNull did not increase HASMC apoptosis above baseline levels. The cells exposed to adenoviruses expressing tumor suppressor genes underwent apoptosis, with Adp53 demonstrating a very high magnitude of cell death (75.27 ±3.52 [SEM]%). AdVHL expression caused 45.36 ±2.55 (SEM)% apoptosis in HASMC. Recombinant adenovirus-mediated VHL expression is efficacious in limiting vascular smooth muscle cell growth in vitro. Overexpression of VHL suppresses HASMC proliferation and regulates apoptosis. Further experiments are indicated to examine whether VHL may be a useful adjunct in limiting myointimal hyperplasia.

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.

Supratentorial haemangioblastoma without von Hippel-Lindau syndrome in an adult: A rare tumor with review of literature

Supratentorial hemangioblastomas (HBLs) are rare, benign vascular tumors of the central nervous system neoplasms. Very scarce literature is available regarding supratentorial HBL without von Hippel–Lindau (VHL) syndrome in an adult. We reviewed the literature and PubMed advanced search showed only a few results of supratentorial HBL without VHL syndrome. We reported a rare case of cystic supratentorial HBL in 39-year-old male affecting the parietal lobe without VHL syndrome. Supratentorial HBL is a rare tumor and supratentorial HBL without VHL syndrome are even rarer. Being a rare entity, not much clinical data is currently available regarding supratentorial HBLs, thus necessitating the need for further reporting and review of such cases.

Pathology characteristics of ocular von Hippel-Lindau disease with neovascularization of the iris and cornea: a case report

Introduction

Retinal hemangioblastoma is one of the most common tumors in von Hippel-Lindau disease. In addition to the classical pathological characteristics of von Hippel-Lindau disease, we report, for what we believe to be the first time, a severe and rare ocular complication characterized by neovascularization in the cornea and iris.

Case presentation

A 41-year-old white man with a long history of retinal hemangioblastoma presented with neovascularization of his iris and cornea as well as corneal perforation. His right eye was blind and painful, leading to a decision of enucleation. On microscopy, the enucleated eye showed neovascularization of the cornea and iris. The cornea was perforated with an expulsive hemorrhage and extruding intraocular contents, including the retina. A large retinal hemangioblastoma was located at the posterior pole adjacent to the optic nerve head. The tumor was mainly composed of large cells with foamy cytoplasm. Bone formation was also present.

Conclusion

Our pathology findings were consistent with previously described features of retinal hemangioblastoma. The present case is unusual because of the co-existing neovascularization in the iris and cornea, which may have led to corneal perforation and vision loss.

A case of vasoproliferative retinal tumor complicated by neovascular glaucoma

PURPOSE

To report a case of vasoproliferative retinal tumor complicated by neovascular glaucoma that showed remission after vitrectomy surgery to remove the tumor.

METHODS

A 78-year-old man was referred to the hospital with a complaint of visual loss in his right eye. Corrected visual acuity was 0.5 in the right eye and 1.2 in the left eye. The right eye showed mild vitreous hemorrhage and an elevated lesion in the lower fundus. Fluorescein angiography demonstrated leakage from the tumor, and a 4-mm lesion of high density was seen on computed tomography, and we diagnosed it as retinal capillary hemangioma. In this case, von Hippel-Lindau disease was negative. During the course of the disease, peripheral anterior synechia and neovascularization was seen in the iris and angle, and vitreous surgery was enforced to remove the tumor because of increased intraocular pressure. The tumor was removed as almost one mass. Histologically, the tumor was composed of glial cells and small vessels proliferation. We diagnosed vasoproliferative retinal tumor.

RESULTS

Seven months after surgery, the intraocular pressure stabilized, and neovascularization of the iris and angle disappeared. Visual acuity was 0.03 due to epiretinal membrane and optic atrophy. There were no signs of recurrence.

CONCLUSION

The vitreous surgery is one of the effective treatment methods against vasoproliferative retinal tumor complicated by neovascular glaucoma.

Upregulation of hypoxia-inducible factors and autophagy in von Hippel-Lindau-associated retinal hemangioblastoma

PURPOSE

To describe pathological and molecular changes of three patients with clinically severe von Hippel-Lindau (VHL)-associated retinal hemangioblastoma (RH) with rapid progression.

METHODS

Medical records, ocular histopathology, and transmission electron microscopy from three cases of VHL-associated RHs at the National Eye Institute were retrospectively reviewed. One eye of each patient was enucleated. Hypoxia-inducible factor (HIF) 1α and HIF2α expressions were identified by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry.

RESULTS

All three cases had rapidly growing RHs that were resistant to multiple conventional therapies and two (patients 1 and 2) were also resistant to multiple intravitreal anti-vascular endothelial growth factor (VEGF) treatments. Macroscopically, all the enucleated eyes had multiple RHs, serous retinal detachment, severe retinal disorganization and focal hemorrhages. Histopathology showed typical RHs composed of vacuolated foamy VHL cells and capillary networks. Retinal gliosis and hemorrhages were also presented. Additionally, T lymphocytes and macrophages infiltrated in the tumors of two patients resistant to anti-VEGF therapy. Immunohistochemistry, and qRT-PCR found upregulation of HIF1α in the retinal lesions of all eyes. Importantly, upregulation of HIF2α was exclusively detected in the two cases with inflammatory infiltration and resistance to anti-VEGF therapy. Ultrastructural images showed autophagy, lipid droplets, glycogen aggregations, and cytoplasmic degeneration in many VHL cells.

CONCLUSIONS

Based on the histopathological and molecular pathological findings, autophagy, inflammation, and/or upregulation of HIF2α could potentially contribute to the aggressive course of RHs, resulting in the resistance to multiple anti-VEGF and radiation therapies in these patients.

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.

Genotype-phenotype correlations, and retinal function and structure in von Hippel-Lindau disease

PURPOSE

To investigate genotype-phenotype correlation and to analyze functional and structural changes in the retina of patients with von Hippel-Lindau (VHL) disease.

METHODS

Thirteen patients from four families (A, B, C and D) with known VHL disease and known mutations in the VHL gene were examined. All patients underwent clinical examination and optical coherence tomography (OCT). Full-field electroretinography (full-field ERG) was performed in twelve patients.

RESULTS

Family A, with deletion of exon 3 in the VHL gene, and family B, with the missense mutation p.R79P, exhibited type 1 VHL characterized by the absence of pheochromocytoma and a high incidence of central nervous system hemangioblastomas. One member of family B exhibited Goldenhar syndrome. A novel missense mutation (p.L198P) was identified in the VHL gene in the patient from family C. This p.L198P mutation caused a phenotype with early onset of a neuroendocrine tumor of the pancreas, bilateral pheochromocytomas, and optic nerve hemangioblastoma. Full-field ERG showed significantly prolonged implicit times of the b-wave and maximal combined a-wave in VHL patients, compared to controls. Examination of the retinal structure in all patients with VHL, using OCT, showed a significant decrease in retinal thickness in VHL patients without ocular hemangioblastomas, compared to controls.

CONCLUSIONS

Our findings support previously established genotype-phenotype correlations. However, we here describe an unusual phenotype with a novel missense mutation, p.L198P, and report the finding that VHL disease can be associated with Goldenhar syndrome. Electrophysiological and structural findings suggest that VHL disease is a progressive, neurodegenerative disease of the retina.

Nervous system involvement in von Hippel-Lindau disease: pathology and mechanisms

Patients with von Hippel-Lindau disease carry a germline mutation of the Von Hippel-Lindau (VHL) tumor-suppressor gene. We discuss the molecular consequences of loss of VHL gene function and their impact on the nervous system. Dysfunction of the VHL protein causes accumulation and activation of hypoxia inducible factor (HIF) which can be demonstrated in earliest stages of tumorigenesis and is followed by expression of VEGF, erythropoietin, nitric oxide synthase and glucose transporter 1 in VHL-deficient tumor cells. HIF-independent functions of VHL, epigenetic inactivation of VHL, pVHL proteostasis, and links between loss of VHL function and developmental arrest are also described. A most intriguing feature in VHL disease is the occurrence of primary hemangioblastic tumors in the nervous system, the origin of which has not yet been entirely clarified, and current hypotheses are discussed. Endolymphatic sac tumors may extend into the brain, but originally arise from proliferation of endolymphatic duct/sac epithelium; the exact nature of the proliferating epithelial cell, however, also has remained unclear, as well as the question why tumors almost consistently develop in the intraosseous portion of the endolymphatic sac/duct only. The epitheloid clear cell morphology of both advanced hemangioblastoma and renal clear cell carcinoma can make the differential diagnosis challenging, recent developments in immunohistochemical differentiation are discussed. Finally, metastasis to brain may not only be caused by renal carcinoma, but may derive from VHL disease-associated pheochromocytoma/paraganglioma, or pancreatic neuroendocrine tumor.

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.

Genotype-phenotype correlation in ocular von Hippel-Lindau (VHL) disease: the effect of missense mutation position on ocular VHL phenotype

PURPOSE

von Hippel-Lindau (VHL) disease is a dominantly inherited, multisystemic tumor syndrome caused by mutations in the VHL gene. This study was conducted to establish genotype-phenotype correlations between the positions of disease-causing missense mutations and the ocular phenotypes of VHL disease.

METHODS

Participants with clinically defined VHL disease and documented germline missense mutations in the VHL gene were identified in a cross-sectional study (n=412). Statistical analysis was used to correlate the position of the missense mutation in either the alpha- or beta-domain of the VHL protein with the ocular disease phenotype.

RESULTS

Missense mutations among study participants were located in 47 of the 213 possible codons in the VHL gene. Almost all mutations (98.5%) were located in one of two structural domains of the VHL protein: the alpha- and beta-domains. alpha-Domain mutations were significantly associated with a higher prevalence of retinal capillary hemangioblastomas (RCHs) compared with the beta-domain mutations (P=0.016). Among patients with RCHs, the prevalence of the lesions in the juxtapapillary position was also significantly higher in patients with alpha-domain mutations (P=0.0017). Conversely, beta-domain mutations correlated with a higher prevalence of peripherally located RCHs (P=0.0104).

CONCLUSIONS

The location of missense mutations in the VHL gene correlates significantly with the prevalence and phenotype of ocular disease, and as such, influences the risk of visual loss in affected patients. These genotype-phenotype correlations can assist in the prognostic counseling and follow-up of VHL patients and may provide a basis for molecular inferences on ocular VHL disease pathogenesis.

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.

Endothelial function of von Hippel-Lindau tumor suppressor gene: control of fibroblast growth factor receptor signaling

von Hippel-Lindau (VHL) disease results from germline and somatic mutations in the VHL tumor suppressor gene and is characterized by highly vascularized tumors. VHL mutations lead to stabilization of hypoxia-inducible factor (HIF), which up-regulates proangiogenic factors such as vascular endothelial growth factor (VEGF). This pathway is therefore believed to underlie the hypervascular phenotypes of the VHL tumors. However, recent studies have identified novel VHL functions that are independent of the HIF-VEGF pathway. In addition, a potential role of VHL in the tumor microenvironment, which carries heterozygous VHL mutations in VHL patients, has been overlooked. Here, we report a novel HIF-independent VHL function in the endothelium. VHL knockdown in primary human microvascular endothelial cells caused defective turnover of surface fibroblast growth factor (FGF) receptor, increased extracellular signal-regulated kinase signaling, and ETS1 activation, leading to increased cell motility in response to FGF and three-dimensional cord formation in vitro. HIF-alpha knockdown in VHL loss-of-function endothelial cells does not impede their elevated in vitro angiogenic activity. Importantly, the elevated angiogenic response to FGF is recapitulated in Vhl-heterozygous mice. Thus, partial loss of function of VHL in endothelium may be a contributing factor in tumor angiogenesis through a HIF-VEGF-independent mechanism.

Internal en bloc resection and genetic analysis of retinal capillary hemangioblastoma

OBJECTIVE

To report the clinical outcomes and molecular genetics of nongermline retinal hemangioblastoma managed by surgical resection.

METHODS

Retrospective case series of 3 patients aged 16 to 46 years treated at a tertiary care referral center (Casey Eye Institute, Portland, Oregon). Tumors 7 to 9 mm in diameter were removed from 3 consecutive eyes (in 3 patients) via internal en bloc surgical resection using a bimanual technique. Samples of DNA from 2 of 3 tumors were tested for von Hippel-Lindau gene (VHL) mutations as a clue to the molecular basis for spontaneously occurring hemangioblastoma. Main outcome measures were morbidity, visual acuity, resolution of macular exudates, and presence of VHL markers.

RESULTS

Visual acuity improved or remained stable in all patients. All 3 developed cataracts, extracted in 2 instances. Histopathological findings were typical of retinal hemangioblastoma in all cases. The cells from one patient's DNA sample showed loss of heterozygosity for the VHL gene, while no genetic abnormalities were detected in the other patient's DNA sample.

CONCLUSIONS

Our patients' favorable outcomes suggest that surgical resection is an option for patients with large retinal hemangioblastomas. In addition, ours may be the first report of retinal hemangioblastoma unassociated with a VHL mutation.

Central nervous system capillary haemangioblastoma: the pathologist's viewpoint

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.

[Retinal angiomatosis. Ocular manifestation of von Hippel-Lindau disease]

Von Hippel-Lindau disease (VHL disease) is a rare multisystem disorder of autosomal dominant inheritance with high penetrance. Inactivation of the VHL-protein leads to an increased expression of hypoxia induced growth factors. Predilection sites for tumor growth are the retina, the central nervous system and various visceral organs. Retinal capillary hemangioblastoma is one of the earliest manifestations of VHL disease. The lifetime risk of permanent visual loss defined as a visual acuity of 0.5 or less is about 35% in gene carriers. It increases to 60% if there is already retinal capillary hemangioblastoma. If VHL disease is suspected, a careful ophthalmological examination should be included in the clinical screening program. Having confirmed the diagnosis, regular ophthalmoscopic monitoring is essential in order to detect developing tumors at an early stage. Therapeutic options for small to medium sized peripheral tumors are laser or cryocoagulation; larger- hemangioblastomas can be treated by brachytherapy using ruthenium plaques, while asymptomatic juxtapapillary tumors can be observed at regular intervals.

Intravitreal anti-vascular endothelial growth factor therapy with pegaptanib for advanced von Hippel-Lindau disease of the retina

OBJECTIVE

This pilot study was designed to provide preliminary data concerning the safety and efficacy of pegylated anti-vascular endothelial growth factor (VEGF) therapy, pegaptanib, for patients with juxtapapillary or large peripheral angiomas secondary to von Hippel-Lindau (VHL) disease.

METHODS

This study was an open label, nonrandomized, prospective, pilot study of intravitreal injections of pegaptanib (3 mg/100 microL), given every 6 weeks for minimum of 6 injections. Five patients with severe ocular VHL lesions were enrolled in the study. The primary outcome of this study was a change of > or =15 letters (3 lines) in best-corrected visual acuity by 1 year. Secondary outcomes included changes in macular thickness, as determined by optical coherence tomography, and changes in fluorescein leakage.

RESULTS

Two of five patients completed the course of treatment and 1 year of follow-up. These two patients had progressive decrease in retinal hard exudate and reduction in central retinal thickness measured by optical coherence tomography. One of these two patients had improvement in visual acuity of 3 lines. No significant change in fluorescein leakage or tumor size was detected in either patient. Lesions in the other three patients continued to progress despite treatment, and these patients did not complete the entire treatment course. One patient developed a tractional retinal detachment. Additional serious adverse events included transient postinjection hypotony in two eyes.

CONCLUSIONS

Intravitreal injections of anti-VEGF therapy (pegaptanib) may decrease retinal thickening minimally and reduce retinal hard exudates in some patients with advanced VHL angiomas. This finding may be related to a reduction in vasopermeability, because there was no apparent effect of treatment on the size of the primary retinal angiomas in this small pilot study.

Molecular pathology of eyes with von Hippel-Lindau (VHL) Disease: a review

BACKGROUND

von Hippel-Lindau Disease (VHL) is an autosomal dominant inherited systemic cancer syndrome. Recently, many advances have contributed to the understanding of VHL pathophysiology.

METHODS

In this article we review recent developments and summarize our findings in VHL molecular pathology related to retinal and optic nerve diseases.

RESULTS

Loss of heterozygosity (LOH) within the VHL gene is detected in the stromal cells surrounding the capillary endothelial cells and admixed with glial cells in ocular hemangioblastomas. This finding is in line with similar findings in VHL-associated CNS hemangioblastoma and renal clear cell carcinomas. Increases of vascular endothelial growth factor (VEGF), hypoxia induced factor (HIF), and ubiquitin are found in ocular hemangioblastomas.Interestingly, tumorlet cells, which are composed of poorly differentiated small cells with prominent dark nuclei and little cytoplasm, as well as several stem cell markers, such as erythropoietin (Epo), Epo receptor (EpoR), and CD133, are present in ocular VHL lesions. CXCR4, a CXC chemokine receptor is also expressed in retinal VHL hemangioblastomas.

CONCLUSIONS

These findings imply that VHL cells with LOH of the tumor suppressor gene, most likely originate from a hematopoietic/vascular lineage. Targeting these proteins and ischemic factors, not VEGF alone, may be a potential therapeutic approach for VHL-associated ocular hemangioblastomas.