Renal cystic diseases: a review

This review aims to assist in the categorization of inherited, developmental, and acquired cystic disease of the kidney as well as to provide a pertinent, up-to-date bibliography. The conditions included are autosomal-dominant polycystic kidney disease, autosomal-recessive polycystic kidney disease, unilateral renal cystic disease (localized cystic disease), renal simple cysts, multicystic dysplastic kidney, pluricystic kidney of the multiple malformation syndromes, juvenile nephronophthisis and medullary cystic disease, medullary sponge kidney, primary glomerulocystic kidney disease, and glomerulocystic kidney associated with several systemic disorders mainly of genetic or chromosomal etiology, cystic kidney in tuberous sclerosis, and in von Hippel-Lindau syndrome, cystic nephroma, cystic variant of congenital mesoblastic nephroma, mixed epithelial stromal tumor of the kidney, renal lymphangioma, pyelocalyceal cyst, peripylic cyst and perinephric pseudocyst, acquired renal cystic disease of long-term dialysis, and cystic renal cell carcinoma and sarcoma. Whereas the gross and histologic appearance of some of these conditions may be diagnostic, clinical and sometimes molecular studies may be necessary to define other types.

Clinicopathological study of vascular endothelial growth factor (VEGF), p53, and proliferative potential in familial von Hippel-Lindau disease and sporadic hemangioblastomas

We examined the clinical characteristics and prognosis in six patients with familial von Hippel-Lindau (VHL) disease and seven with sporadic hemangioblastomas. The expression of vascular endothelial growth factor (VEGF), p53 protein, and proliferative potential with Ki67 monoclonal antibody (MIB-1) was compared using immunohistochemical methods between sporadic and VHL disease-associated hemangioblastomas. Patients with sporadic CNS hemangioblastomas were treated by total removal of the tumors, and they had a good long-term prognosis without neurological deficits on recurrence. However, patients with familial VHL disease often had multiple hemangioblastomas in the CNS and visceral tumors. Even if total removal of CNS hemangioblastomas in patients with VHL disease was performed initially, small multiple hemangioblastomas recurred during long-term follow-up in areas remote from the primary region resected by surgery. All of the hemangioblastomas displayed extensive overexpression of VEGF protein, with moderate to marked proliferation of blood vessels. The MIB-1 indices showed low values of 0.8% as the mean, with a range of 0.03%-2.1% for all the hemangioblastomas. None of the hemangioblastomas expressed p53 protein. The hemangioblastomas in patients with VHL disease were multiple in the CNS and were combined with visceral tumors. Patients with VHL disease had a poor long-term prognosis, in contrast to those with sporadic hemangioblastomas. The immunohistochemical findings for VEGF protein, p53 protein, and MIB-1 did not differ significantly between the sporadic and VHL disease-associated hemangioblastomas.

von Hippel-Lindau syndrome: target for anti-vascular endothelial growth factor (VEGF) receptor therapy

von Hippel-Lindau (VHL) syndrome is a familial cancer syndrome caused by germline mutations in the VHL tumor suppressor gene. Mutations in the VHL gene result in the constitutive stabilization of transcription factors hypoxia-inducible factors 1alpha and 2alpha, which bind to specific enhancer elements in the vascular endothelial growth factor (VEGF) gene and stimulate angiogenesis. This increase in angiogenesis under normoxic conditions in key target organs such as the brain, kidney, and eye leads to high morbidity and reduced life expectancy. Drugs designed to block the VEGF signaling pathway may prevent the long-term complications of the disease. To test this hypothesis, a clinical study was initiated to evaluate the effect of the VEGF tyrosine kinase receptor inhibitor SU5416 in patients with VHL syndrome. Preliminary data on SU5416 indicate that it is well tolerated when administered chronically in such patients. However, since little is known about the long-term use of such inhibitors, patients will need careful monitoring. Data obtained from monitoring these patients will provide valuable information for adjuvant treatment trials in cancer patients.