Spontaneous single duct discharge is the main indication for galactography. This abnormality has in most cases a benign aetiology (> 90%). With a meticulous technique and sufficient experience, the ducts can be cannulated in 95% of the cases. A nipple adenoma with a blood stained discharge is seldom to pass for cannulation. Because cytology of the nipple discharge is not always positive in case of intraductal proliferations, microdochectomy must be used to obtain the differential diagnosis. Galactography shows multiple normal duct variations, depending on age, surrounding tissue, and a possible history of lactation. Pathologic images can be seen in dystrophic breasts, solitary papillomas, (juvenile) papillomas or (intraductal) carcinomas. In addition to high frequency ultrasonography (> or = 10 MHz), which is able to visualise the retro-areolar and superficial ducts, galactography can give a more detailed and better overview of the pathology.