VHL and retinal hemangioblastoma: A clinical diagnosis of VHL disease can be established under the following conditions: the presence of at least two central nervous system hemangioblastomas (including retinal hemangioblastomas); the presence of at least one central nervous system hemangioblastoma and one of the other aforementioned manifestations; or the presence of any one of the aforementioned manifestations along with either a pathogenic mutation in the VHL gene or a first-degree familial relationship with an individual diagnosed with VHL disease (Chittiboina and Lonser, 2015).