Atypical ductal hyperplasia (ADH) is an abnormal production of cells within the duct system of the breast. Women who have atypical ductal hyperplasia have an increased risk of breast cancer.

Atypical ductal hyperplasia is usually discovered by mammography and diagnosed with a biopsy of the breast. Women who have ADH are usually followed closely by a health professional and have a breast exam every 6 months and a mammogram once a year.

By	Healthwise Staff
Primary Medical Reviewer	Joy Melnikow, MD, MPH - Family Medicine
Specialist Medical Reviewer	Douglas A. Stewart, MD - Medical Oncology
Last Revised	August 18, 2009