Usual ductal hyperplasia (UDH)
This article was last reviewed and updated on June 4, 2018.
by Livia Florianova, MD FRCPC
Usual ductal hyperplasia (UDH) is a non-cancerous condition that develops in the breast.
It is caused by an increased number of cells in small channels called ducts.
Usual ductal hyperplasia is a very common condition that happens more often in younger women.
Adult breast tissue is composed of small structures called glands which are organized into groups called lobules. Under certain conditions, these glands can produce milk, which is transported to the nipple by a series of small channels called ducts. The inside of both glands and ducts is lined by specialized cells called epithelial cells.
Usual ductal hyperplasia is a non-cancerous (benign) condition of the breast that shows an increased number of epithelial cells which fill and expand ducts. It is a very common condition in young women but can happen to women of all ages.
Usual ductal hyperplasia may be diagnosed in a biopsy or resection specimen. In most cases, the tissue has been removed for another reason (for example a cancer in the same breast) and usual ductal hyperplasia is a secondary diagnosis.