Photomicrographs showing mammary gland of rats in the control and treatment groups (200x). There was no apparent hyperplasia and no clear secretion in the mammary ducts and lumens in the control group (a) and the FPE-treatment-alone group (b). However, severe mammary gland hyperplasia (MGH), lobule increase (LI), acinar (MA) increase, mammary duct (MD) and lumen ectasia, and mammary duct and lumen secretion were observed in the estradiol benzoate and progestin treatment group (c). The pathology of the mammary glands of the model rats improved upon treatment with FPEs at 30 ml/kg (d), 15 ml/kg (e) and 5 ml/kg (f). Scale bar, 100 μm.