Twin vessels are where a tiny vein and a tiny artery are paired near the optic disk. However, the Utrecht team recommends using annual ultrasound for most follow-ups, to reduce the exposure to radiation. Radiation is known to cause genetic mutation, which may be associated with the transformation of normal cells into tumor cells. This group advocates a conservative approach to treatment of kidney tumors. Only solid and progressively growing lesions with a diameter of more than 3-4 cm.
Partial nephrectomy is an attractive alternative and has produced favorable results. . . .
If bilateral nephrectomy is indicated, kidney transplantation is a reasonable option in the long run. However, the risk of developing any cancer is increased in people whose immune system is suppressed. One may speculate whether immunosuppression enhances the development of VHL lesions. Diagnosis of pheochromocytomas remains tricky. This group recommends refraining from treating pheochromocytomas until they become chemically active, or until the tumor shows steady growth.