Von-Hippel-Lindau (VHL) syndrome is an autosomal dominant disease caused by a germline mutation in VHL tumor suppressor gene.
The disease, which was first described by Eugen von Hippel and Arvid Lindau in the 20th century, affects one in every 32,000 individuals in the US.
There is no specific treatment guideline followed to treat VHL syndrome. In general, long-term treatment procedures to treat the VHL syndrome can increase the risk of developing psychological disorders, which can also induce somatic ailments. Therefore, VHL syndrome requires an individualized treatment plan, depending on the clinical features.
Medical Marvels - Von Hippel-Lindau Disease
Effective management of the disease phenotypes depends on the size and location of the tumors. Due to the occurrence of tumors in multiple organs, establishing a comprehensive treatment strategy for VHL syndrome is complex. Thus, most of the interventions are basically related to a particular disease phenotype.
In the case of large and fast-growing hemangioblastomas, surgical removal of the tumor is the most commonly recommended option. Besides surgery, non-invasive high dose radiotherapy such as stereotactic radiosurgery is another option to accurately target brain tumors.
In cases of extensive spinal cord tumors, preoperative arterial embolization may be included as a part of disease management.
Surgery is the most widely recommended option to remove adrenal gland tumors. Patients are generally recommended to take alpha-adrenergic and/or beta-adrenergic blockers for 7 to 10 days before the surgery to reduce the risk of high blood pressure induced by high catecholamine levels during the surgery.
This surgery generally involves complete or partial removal of the adrenal gland. In cases that require complete removal of the adrenal gland, patients are generally prescribed hormonal therapy to fulfill the need for adrenal hormones.
Partial removal of the adrenal gland is the choice of surgical intervention for pediatric patients. Minimally invasive laparoscopic surgery is also effective in some cases.
The early diagnosis and treatment of retinal tumors are necessary to avoid vision loss. Xenon, diathermy, cryocoagulation, and lasers are different therapeutic interventions that can b e applied to treat the lesion. The selection of the specific treatment protocol will depend on the size and position of the lesion.
In cases where the conventional method fails to provide success, external beam radiotherapy is applied to restrict the progression of the condition
Renal cell carcinoma
The surgical removal of fast-growing or large kidney tumors that are larger than 3 centimeters (cm) is the best option to treat renal cell carcinoma (RCC). However, this treatment option is only possible when the allowable size and location of the tumor are suitable for conducting the process.
Other treatment options for RCC include radiofrequency ablation, which involves treatment of the tumor with radiofrequency waves. Radiofrequency ablation can be applied in the case of tumors that are smaller than 3 cm. Laparoscopic and percutaneous radiofrequency ablation therapies have some tendency to cause complications; therefore, frequent follow-up is required.
Cryoablation, which is the treatment of the affected tissue with extremely cold probes to prepare them for removal, is also an option. Cryoablation is widely used in the treatment of RCC to avoid multiple surgeries. Additionally, this treatment option can also be applied to small lesions.
Renal transplantation is conducted in cases of bilateral nephrectomy.
Pancreatic cysts and neuroendocrine tumors
Pancreatic cysts are generally harmless and do not require any surgical intervention. .
Comparatively, pancreatic endocrine tumors require constant follow-up because of their tendency to spread and become malignant. Surgical removal is recommended for tumors larger than 3 cm or those that exhibit a rapid growth rate.
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Given the complexity of VHL syndrome, individuals who are diagnosed with the disease, those with a VHL pathogenic mutation without any clinical manifestation, as well all at-risk relatives who have not gone through genetic testing, will require close monitoring by healthcare professionals for better disease management.
A routine surveillance protocol for VHL syndrome includes:
- Annual ophthalmic examinations starting at early childhood for the screening of retinal angioma
- Brain MRI in every 1-3 years starting at adolescence for the screening of CNS hemangioblastoma
- Abdominal MRI or ultrasound examination in every 12 months starting at the age of 16 years for the screening of kidney and pancreatic tumors
- Annual blood pressure monitoring and urine test for catecholamine metabolites for the screening of adrenal gland tumors
- For families with a high risk for adrenal tumors, adrenal imaging and detection of plasma normetanephrine levels starting from the age of 8 years are recommended.
About 80% of the patients with VHL syndrome have an affected parent, whereas only 20% will develop the condition through de novo mutations.
Genetic counseling, which includes proper medical explanations on the nature, inheritance, and implications of the disease to the affected or at-risk parents, is an important approach to prevent disease transmission over generations. Molecular testing is recommended for parents of an affected individual to look for a mutation. If the pathogenic variant is not known, ophthalmic screening and abdominal ultrasound are other options that should be suggested to both parents.