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Biomedical subjects

Christophe Laurent

Publications and source records attributed to Christophe Laurent.

24 records · Page 2Linked to original sources

Multiple telangiectatic focal nodular hyperplasia: vascular abnormalities.

The aim of this study was to look for vascular abnormalities in the liver of patients with multiple telangiectatic focal nodular hyperplasia. Four patients, all women on oral contraceptives, were included in this study. In none of the cases was the diagnosis of multiple telangiectatic focal nodular hyperplasia made preoperatively. In the nodules, the pathological aspect was quite characteristic with dilated sinusoidal areas surrounding compact areas. Compact areas comprised portal tract-like structures with vessels, mainly thickened arteries, usually amidst an inflammatory reaction. A ductular reaction of varied intensity was present in three cases. The non-nodular liver was grossly normal. However, in rare areas, there were obvious or minor vascular abnormalities looking like minimal abnormalities seen inside telangiectatic nodules. These results seem to support the concept that multiple telangiectatic focal nodular hyperplasia is a non-specific reaction to focal ischemia induced by various mechanisms such as hepatic vein thrombosis induced, perhaps, by oral contraceptives.

Adult↗

Familial liver adenomatosis associated with hepatocyte nuclear factor 1alpha inactivation.

BACKGROUND & AIMS: Germline mutations in hepatocyte nuclear factor 1alpha (TCF1/HNF-1alpha) are associated with maturity-onset diabetes of the young type 3 (MODY3), and somatic biallelic inactivations of the gene are found in hepatocellular adenomas and liver adenomatosis. This study investigated cosegregation of HNF-1alpha germline mutations with diabetes and liver adenomatosis in 2 families. METHODS: Two unrelated patients with liver adenomatosis and harboring HNF-1alpha germline and somatic mutations were studied. Subsequently, we screened 9 relatives in the 2 independent families for diabetes, hepatocellular adenomas, and HNF-1alpha germline mutations. RESULTS: In family A, a father and his son presented with an intraperitoneal hemorrhagic rupture of a liver adenomatosis without diabetes. A heterozygous R229X germline mutation was identified in HNF-1alpha in the father and his son and also in his second 27-year-old son without hepatocellular adenomas. In family B, a diagnosis of liver adenomatosis was made fortuitously in a 14-year-old girl. A heterozygous G55fsX57 germline mutation in HNF-1alpha was identified in this patient, her diabetic father, and her 2 sisters. Systematic exploration showed liver adenomatosis in the 2 sisters. Somatic inactivation of the second HNF-1alpha allele was found in liver tumors in both families. CONCLUSIONS: This study describes familial liver adenomatosis and shows the association with germline HNF-1alpha mutations in adults and children. It also highlights the importance of screening for hepatocellular adenomas, diabetes, and HNF-1alpha germline mutations in relatives of patients with liver adenomatosis. Finally, prevalence of liver adenomatosis remains to be evaluated in MODY3 subjects.

Adenoma↗

Molecular profiling of hepatocellular carcinomas (HCC) using a large-scale real-time RT-PCR approach: determination of a molecular diagnostic index.

The aim of this study was to develop and validate a molecular index for the diagnosis of hepatocellular carcinoma (HCC) based on genes whose specificity and level of expression are the most discriminating for the diagnosis of HCC. The level of expression of 219 genes was assessed with a real-time reverse transcription-polymerase chain reaction approach in a training set of samples including normal livers (15), cirrhosis (12), and HCC (16). The most informative genes were selected for the molecular index. This index was prospectively validated in a new set of 40 samples (testing set) and in a set of 45 cirrhotic macronodules. 44 out of the 219 genes were differentially expressed in HCC. 13 out of these 44 genes were finally selected for the molecular index according to their diagnostic performance and after exclusion of most redundant genes. Using this index, 42 out of 43 samples of the training set and 39 out of the 40 samples of the testing set were correctly ranked as HCC or not HCC (normal liver or cirrhosis). The index also enabled correct ranking of 44 out of 45 cirrhotic macronodules into 2 groups: benign (including macroregenerative and dysplastic macronodules) and malignant macronodules. This molecular diagnostic index is an efficient tool both for identification of overt HCC as well as minute lesions (cirrhotic macronodules). It might be useful to correctly diagnose borderline lesion or small well-differentiated hepatocellular carcinomas whose diagnosis is often difficult on a histopathological basis.

Adolescent↗

The identification of small nodules in liver adenomatosis.

BACKGROUND/AIMS: Liver adenomatosis is characterized by the presence of multiple adenomas of various sizes in the liver. The aim of this study was to characterize the morphology of small nodules which can be difficult to identify. METHODS: Seven patients included in this study underwent surgery for the removal of one or several nodules. All, but one, were females. Three out of seven presented with acute bleeding. Five had six or more nodules at presentation, and two only one, who developed nodules later on during follow-up. RESULTS: All of the large nodules that were >2 cm, except one, were typical adenomas with or without hemorrhagic areas. Smaller nodules (1-2 cm), some of which discovered on the resected specimen were either typical adenomas or non-typical nodules. These non-typical nodules were characterized by a polylobulated aspect with steatotic zones, and in between, bands of non-steatotic hepatocytes with portal tracts-like structures containing occasional cytokeratin 7 and less often cytokeratin 19 positive biliary cells. Numerous steatotic foci were also seen in four cases. They were isolated or grouped forming microadenomas or non-typical micronodules (<1 cm) containing biliary elements. Our findings lead to the following hypothesis: adenomatosis is characterized by the simultaneous occurrence of multiple adenomas; if several adenomatous foci expand at the same time in the same area, they will form one polylobulated nodule containing non-adenomatous tissue with portal tracts in between areas of adenomatous tissue (non-typical micronodule). Such a small micronodule may in turn expand and join another micronodule to form a bigger one by the same process (non-typical nodule). As nodules grow, their non-adenomatous components including hepatocytic plates and portal tracts constituents will progressively disappear to end up with the classical aspect of an adenoma. CONCLUSIONS: This hypothesis supports the concept that non-typical nodules/micronodules are adenomas precursors. However, they can be difficult to classify since they resemble focal nodular hyperplasia precursor.

Adenoma↗