Continuous angiogenesis inhibition in the treatment for von Hippel-Lindau-related hemangioblastomas of retina and spinal cord

Aggressive dissemination of central nervous system hemangioblastoma without association with von Hippel–Lindau disease: A case report and literature review

Background:

Hemangioblastomas (HBs) typically present with benign behavior and are most commonly found in the posterior fossa. Multiple central nervous system (CNS) HBs are usually associated with von Hippel–Lindau disease, and leptomeningeal dissemination of sporadic HBs is extremely rare. A review of the literature identified 30 cases of leptomeningeal dissemination of sporadic HBs previously published in the literature.

Case Description:

We report the case of a patient who was diagnosed with multiple CNS HBs with aggressive progression 6 years after resection of a posterior fossa HB. He underwent multiple surgeries and died 4 years after the diagnosis of the first spinal dissemination.

Conclusion:

Dissemination of sporadic HBs is rare and aggressive disease evolution is usually observed. Further studies are necessary to determine the optimal therapeutic options.

Current concepts on ocular vascular abnormalities in the phakomatoses

BACKGROUND

Neurofibromatosis, Von Hippel Lindau disease, and tuberous sclerosis complex are classified under the term phakomatoses. They are characterized by ocular vascular abnormalities such as vascular tortuosity, corkscrew retinal vessel configuration, moyamoya-like aspect, microaneurysms, hemangioblastomas, and focal sheathing of retinal arteries, possibly due to abnormal formation, migration, and differentiation of neural crest cells. These alterations can be the first sign or the hallmark of disease and can be related to vasoproliferative tumors.

PURPOSE

Novel imaging technologies in ophthalmology, such as near-infrared reflectances and spectral domain optical coherence tomography, have improved our knowledge in the diagnosis of these pathologies. Previously undetected macular vascular alterations have been reported in phakomatoses using optical coherence tomography angiography. This review will summarize the ophthalmic vascular abnormalities and novel imaging methods in the phakomatoses.

CONCLUSION

Active research is being led into the ophthalmic management of these conditions and their complications, and owing to elevated vascular endothelial growth factor production from hemangioblastoma, hamartoma, and retinal vascular proliferative tumors, increasing interest in this line of therapy has been conducted although research is still ongoing in this area.

Metastasis of Renal Cell Carcinoma to Spinal Hemangioblastoma in a Patient with von Hippel–Lindau Disease: A Case Report

von Hippel–Lindau (VHL) disease is characterized by neoplastic and cystic lesions, such as central nervous system (CNS) hemangioblastoma and clear cell renal cell carcinoma (RCC), arising in multiple organs. Here, we report a case of an RCC that metastasized to a spinal hemangioblastoma in a patient diagnosed with VHL disease. This is a unique case study because visceral neoplasms rarely metastasize to the CNS. The patient had undergone posterior fossa surgery for the removal of hemangioblastomas in the right cerebellar hemisphere as a child. He was diagnosed with RCC at the age of 20 years, and he underwent partial nephrectomy at the age of 35 years. The patient underwent surgical removal of a spinal tumor from Th8, which was also diagnosed as a hemangioblastoma at the age of 40. However, the residual spinal tumor rapidly regrew within 1.5 years. A second surgery was performed due to progressive leg motor weakness. The resected tumor from the second surgery had two distinct components between the tumor center and the margin. Immunohistochemistry of CD10, PAX 8, and inhibin A demonstrated the predominant region of the tumor was RCC. Pathological findings confirmed tumor-to-tumor metastasis of the RCC migrating into residual spinal hemangioblastoma. It can be challenging to distinguish hemangioblastoma from RCC in neuroimaging. We suggest that tumor-to-tumor metastasis should be considered as a differential diagnosis if benign tumors grow rapidly, even if the pathological diagnosis does not initially confirm malignancy. The biological mechanisms of RCC migrating into residual hemangioblastoma are discussed.

Role of thalidomide, senicapoc, and sodium butyrate in choroidal neovascularization

Choroidal neovascularization (CNV) is the hallmark of wet age-related macular degeneration (AMD), a leading cause of irreversible blindness in the modern world. The objective for this study was to investigate the therapeutic potential of known antiangiogenic agents: thalidomide, senicapoc, and sodium butyrate. Dose-dependent effect of the agents on growth of ARPE-19 cells and human umbilical vein endothelial cells (HUVECs) was investigated with cell counting assays. Half-maximal inhibitory concentrations of thalidomide (765 μM and 1520 μM), senicapoc (50 μM and 79 μM), and sodium butyrate (933 μM and 557 μM) were determined for HUVECs and ARPE-19 cells, respectively. Immunofluorescence analysis showed decrease of VEGFA expression in both ARPE-19 cells and HUVECs after treatment only with thalidomide but not with senicapoc or sodium butyrate. Efficacy of the agents was studied in vivo with laser-induced CNV in C57BL/6 mice. Thalidomide (24 μg), senicapoc (4 μg), or sodium butyrate (100 μg) was intravitreally injected the day after CNV induction. Thalidomide, senicapoc, and sodium butyrate inhibited CNV size by 56%, 24%, and 21% respectively on day 7 post-laser. Thalidomide also reduced cobalt chloride induced increase of VEGFA mRNA in ARPE-19 (-33%) and protein in culture medium (-20%). Our results suggest that thalidomide may have more therapeutic potential than senicapoc or sodium butyrate for treatment of CNV or wet AMD.

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.