[Molecular changes in adenocarcinoma of the small intestine associated with Peutz-Jeghers syndrome].

The presence of molecular alterations in the c-K-ras and p53 genes in a small bowel adenocarcinoma arising in a case of Peutz-Jeghers syndrome is reported. The absence of mutations at codon 12 and 13 of the c-K-ras gene in the hamartoma and carcinoma indicates that this oncogene does not contribute to its development. On the other hand, p53 protein overexpression was detected in a small proportion (5-10%) of adenocarcinoma cells. Our findings suggest that p53 inactivation occur in late stages of tumour progression.