RESUMEN
A disproportionately large number of young (50 years); those from young black patients presented more often with a low methylation phenotype (CIMP-L) and high levels of microsatellite instability (MSI-H). Furthermore; as determined by real-time PCR using probe technology; the tissues from35of young blacks showed mutations within exon 1 of the KRAS gene. The BRAF-V600E mutation was only evident in the case of a single young black patient. Based on these results it seems likely that a proportion of CRC cases in young black patients from South Africa develop through the accumulation of mutations resulting in a mismatch repair deficiency linked to MSI-H and; possibly; germline mutations in the mismatch repair genes. The features in these patients are consistent with a diagnosis of the Hereditary Non-Polyposis Colorectal Cancer (HNPCC) syndrome. This finding has important implications for patient management and suggests that family members may be at high risk for CRC
Asunto(s)
Población Negra , Neoplasias Colorrectales , Adulto JovenRESUMEN
A 28 yr old Zulu presented with a painful swelling in the right hypochondrium and severe swelling of the legs of short duration. The serum alpha-fetoprotein concentration was over 2 X 10(5) ng/ml and imaging showed a large hepatic mass-lesion. Radionuclide venography revealed no flow through the inferior vena cava but flow through a large collateral vessel. Contrast venography showed the upper portion of the inferior vena cava to be occluded: large collateral vessels arose from the lower vena cava and the iliac veins. The histological features were those of longstanding hepatic venous outflow obstruction with irregular centrizonal and portal fibrosis: severe acute centrizonal congestion was not seen. This combination of findings indicates the presence of both membranous obstruction of the inferior vena cava, a rare developmental abnormality which predisposes to hepatocellular carcinoma formation, and invasion by the tumour of the inferior vena cava via the hepatic veins, an uncommon complication of hepatocellular carcinoma.