Epidemic of breast enlargement in an Italian school.

An outbreak of breast enlargement in girls and boys attending a school in Milan, first noted in November, 1977, was followed up until the end of 1978. 213 boys aged 3-14 years and 110 girls aged 3-7 years were studied; control children attending five other schools were also examined. In total 1647 boys and 476 girls were examined. Breast enlargement was significantly more common in boys (29.0%) and girls (21.6%) aged 3-5 years, boys (58.0%) aged 6-10, and girls (67.1%) aged 6-7 from the school in Milan, than in age and sex matched children at control schools. Breast enlargement was not pronounced and disappeared within 8 months. Hormonal determinations were within normal limits except for 17 beta-oestradiol which was slightly raised. Although oestrogen contamination was not detected when samples of school meals were tested, an uncontrolled supply of poultry and beef was suspected as being the cause of this outbreak.