SMALL-BOWEL CARCINOMA IN HEREDITARY NONPOLYPOSIS COLORECTAL-CANCER

A 53-yr-old man, a member of a hereditary nonpolyposis colorectal canc er (HNPCC) family, with previous colonoscopic polypectomies, presented for persisting vomiting and marked signs of dehydration. Previous rad iological and endoscopic examinations of the upper digestive tract wer e negative, with the exception of the presence of a duodenal adenomato us polyp. Enteroclysis led to a diagnosis of obstruction at the Treitz angle due to a moderately differentiated adenocarcinoma, Microsatelli te instability was demonstrated in the DNA extracted from the tumor. T he patient was the carrier of a mutation in the intron 13 of the hMLH1 gene, one of the four mismatch repair genes known to be responsible f or HNPCC. (C) 1998 by Am. Cell. of Gastroenterology.