Which of the following statement(s) is/are true concerning intraductal papilloma?

a. This lesion is the most common cause of bloody nipple discharge

c. A nonpalpable lesion can often be diagnosed with ductography

Intraductal papilloma represents the most common cause of bloody nipple discharge, although in half of the cases, the discharge is serous. Since the average size of an intraductal papilloma is 3–4 mm., they are rarely palpable. Ductography may demonstrate the lesion, or it may be found after subareolar duct excision performed to treat the discharge. An isolated intraductal papilloma is not considered premalignant nor does it place the patient at increased risk for breast cancer. Unlike isolated papillomas, diffuse papillomatosis is associated with an increased risk of breast cancer, perhaps as high as in 40% of women.