Mutagens in human breast cyst fluid.

Cyst fluids aspirated from patients presenting with palpable cysts of the breast were analysed for mutagenic activity, as determined by the Ames test. Of the 439 women studied, 9.6% had mutagen-positive fluids. There was no obvious relationship between the presence of mutagen-positive fluids and clinical or epidemiological details of the women from which they were obtained. Preliminary characterisation of the mutagenic activity suggested that the responsible agents have diverse chemical properties.