Unexpected breast cancer detection after outpatient biopsy for benign lesion.

At the Istituto Nazionale Tumori of Milan, in its Outpatient Department, 1302 breast surgical biopsies were carried out in 1978. Fibroadenomas occurred in 44.2% and benign dysplasias in 39.3%. Sixty-two cancers (4.8%) and 23 atypical hyperplasias (1.8%) were unexpected findings, with an increasing incidence in women over 50. Seventy-nine duct resections were performed for significant nipple discharge and revealed 5 unexpected carcinomas and 28 papillomas or papillomatosis. In our opinion and experience, this procedure of performing breast biopsy in the presence of a solid lump in women over 30 without hospitalization improves early detection of cancer, lowers costs, cuts down admission waiting lists and increases the number of women who better accept a surgical diagnosis and treatment.