Hemangioblastomas (HBs) of the central nervous system are benign tumors and
occur as sporadic (sp) tumors (75%) or as a manifestation of the von Hippe
l-Lindau (VHL) disease (25%). VHL-disease is an autosomal dominant disorder
characterized by HBs of the central nervous system and retina, renal cell
carcinoma (RCC), phaeochromocytoma (PHEO), islet tumors of the pancreas, an
d endolympatic sac tumors as well as cysts and cystadenoma in the kidney, p
ancreas and epididymis. In VHL patients a large spectrum of germline mutati
ons in the VHL gene has been detected. In spHBs VHL alleles are reported to
be inactivated in up to 50% of the tumors. To our knowledge the involvemen
t of other genes in spHBs has not been investigated. To elucidate the oncog
enesis of spHBs, we performed CGH on 10 spHBs to screen for chromosomal imb
alances throughout the entire tumor genome. Aberrations most frequently det
ected are losses of chromosomes 3 (70%), 6 (50%), 9 (30%), and 18q (30%) an
d a gain of chromosome 19 (30%). Based on these frequencies and the co-occu
rrence of these aberrations in the analyzed tumors we hypothesize that loss
of chromosome 3 (harboring the VHL gene) is an early event in the oncogene
sis of spHBs, followed by loss of 6, and then losses of chromosomes 9, 18q
and gain of chromosome 19. Comparison of the chromosomal imbalances in spHB
s to those previously reported in RCCs and PHEOs reveals that the pathway o
f spHBs shows similarities to both the RCCs and PHEOs.