Gynaecomastia and premature thelarche in a schoolchildren population of northern Italy.

The prevalence and incidence of gynaecomastia and thelarche have been studied in pre-school children and school children belonging to different socio-economical classes in two Northern Italian Cities: Milano and Mantova. The children selected underwent three clinical examinations in their own school by the same examinator. The highest prevalence (36.6%) of breast enlargement was observed in nursery children until 2 years of age in Milano. Age and sex specific incidence rates were higher in Milano than in Mantova except in boys 11-14 years old. Assumption of drugs which might induce gynaecomastia thelarche was excluded. Relative risks calculated for veal and chicken must suggest that these are not relevant in the etiology of breast enlargement.