Deletion (5q) in a desmoid tumor of a patient with Gardner's syndrome

Desmoid tumors are associated with as many as 20% of cases of familial adenomatous polyposis (FAP) and Gardner's syndrome. In the present study, four specimens from different regions of a massive intraabdominal desmoid tumor from a 23-year-old white male with Gardner's syndrome were analyzed cytogenetically. Two different clonal abnormalities were observed. Two of the four specimens analyzed showed a del(5)(q14q31), which involves the region q21→22 where the familial adenomatous polyposis gene is localized. In the two other specimens, a balanced translocation involving chromosomes 3 and 4 and an inv(4) was detected. Our findings confirm previous reports about the importance of chromosome defects on 5q in development of desmoid tumors, particularly in patients with Gardner's syndrome.