VHL and polycythemia: They highlighted 3 types of VHL associated with 3 subtypes classification: Type 1, not from pheochromocytomas and mutations in patients with this type of VHL; Type 2, which has the appearance of pheochromocytomas and can be further subdivided into 3 subtypes: low (type 2A), and high (type 2B) risk of RCC, type 2C families with pheochromocytoma only, type 3 Chuvash polycythemia..