RENAL CELL CARCINOMA
In cross-sectional studies, 25–30 % of VHL patients have had clear cell RCC (Maher et al. 1990a). The risk of RCC in VHL disease was initially underestimated because the mean age at RCC diagnosis (44 years) is older than for retinal angioma (25 years) and cerebellar hemangioblastoma (29 years), but since emerging as the leading cause of mortality in VHL disease (Maher et al. 1990a), the importance of presymptomatic renal surveillance has been recognized. The clinical presentation and risk of metastasis in RCC complicating VHL disease are similar to those of sporadic nonfamilial Tumours. However, Tumours in VHL disease occur at an earlier age and are often multiple and bilateral. Renal cysts may be detected in the second decade, and RCC has been detected as early as the age of 16 years. RCC may arise from the wall of renal cysts, and complex cysts require careful follow- up. Renal Tumours and cysts may be detected by ultrasonography or computed tomography, but MRI scanning is preferred for routine screening as it is more sensitive than ultrasonography and avoids repeated radiation exposure. The management of renal cancer in VHL disease is motivated by a conservative nephron-sparing approach. Thus it is usual to follow small asymptomatic Tumours by serial imaging until they reach about 3 cm diameter. At that stage, conservative renal surgery is performed with the aim of conserving functioning renal tissue for as long as possible. Follow-up of VHL patients treated by nephron-sparing surgery reveals a high incidence of local recurrence from new primary Tumours, but a low risk of distant metastasis. In contrast, 25 % of VHL patients with more advanced RCC (>3 cm) develop metastatic disease (Walther et al. 1999a). Repeated partial nephrectomies may eventually compromise renal function, and in such cases, dialysis is instigated – through renal transplantation is also an option. It appears that immunosuppression does not affect adversely the underlying course of VHL disease, and the prognosis of VHL patients after transplantation appears similar to that of other comparable groups (Goldfarb et al. 1998).