Anatomical Understanding of Ductal and Lobular Cancer
Ashley Davidoff MD
Every woman needs to know the facts. And the fact is, when it comes to breast cancer, every woman is at risk.
Breast Cancer Awareness
The blog is dedicated to Breast Cancer Awareness Month 2015 which also incorporates National Mammography Day (October 16th).
The intention of the blog is to facilitate the understanding of the two main types of breast cancer; ductal and lobular forms.
In order to understand the main types of breast cancer it is important to understand the structural makeup of the breast.
The breast is one of a paired organ system and is an accessory organ of the female reproductive system. It consists of the outer skin and nipple, the inner glands and ducts which are supported by adipose (fatty) tissue. The glands produce milk during lactation and the ducts transport the milk from the glands to the nipple.
Physiologic changes during the menstrual cycle and pregnancy affect the structural appearance of the tissue.
Breast Cancer
Breast cancer most commonly begins from cells located in either the lobules of the breast or the ducts. Breast cancer arising from the lobules is called lobular cancer and when it arises from the ducts it is called ductal cancer. Most breast cancers start in the ducts.
Lobules and Ducts – Where are they and what are they?
Each breast contains 15 to 20 lobes of glandular tissue, arranged like the petals of a flower and the best example is a daisy.
Daisy Like Structure of the Breasts
The petals of the daisy represent the lobes (glands) of the breast and they become confluent via the ductal systems at the nipple.
The lobes are further divided into smaller lobules (small parts of the lobe) that produce milk for breast feeding.
The Lobes Lobules and Ducts of the Breast
This art piece demonstrates five of the 15-20 lobes of the breast. The lobes (white structures) are further divided into small florets (lobules – small pink flowers in the lobe) that reside in the lobe. The lobules have multiple small ducts (intralobar ducts) that join to form a single larger duct outside the lobe called the extralobar duct (pink tubes) which empty into the nipple.
The lobes and ducts are distributed radially around the breast like the dials of a clock. The nipple is at the apex and the glands and ducts surround the nipple.
The AiA rendering shows a woman in elegant dress. The histological (tissue) makeup of the breasts with glandular tissue, ducts, and supportive adipose tissue are part of the decor of the dress. Artistically one could view this piece as a dress with Vogue like elegance. Alternatively it can be viewed as an art piece that combines the aesthetics of dress design and the aesthetics of biology.
Lobes Ducts and Nipples in Purple
This AiA art piece shows the lobular and radial organization of the ducts, and glands, with interposing adipose (fat) and connective tissues. The axillary tails of Spence extend to the axilla help support the breast tissue. Artistically the breasts are given a light feminine color matched with a deep strong purple color showing two forces of femininity.
Glandular Makeup of the Breast
This artistic rendering of the breast shows the lobes that make up the glandular tissue of the breast, each subtended by a lactiferous duct that exits at the nipple. Image b shows a single lobe made up from 20-40 lobules that look like white clumps of grapes or florets. The lobules (c) have an extra-lobular ductule that connects to the main duct. The lobules are composed of tear dropped shaped glandular sacs called acini, (d) or alveoli which are lined by an inner epithelium (e) that contains cuboidal (square shaped) cells which secrete milk and outer smooth muscle cells that enable the glandular tissue to contract and help transport the milk to the nipple .
Each acinus empties its secretion into a intralobular duct. All the intralobular ducts join to form an extralobular duct.
showing the cuboidal (square) cells in the acinius (grape shaped structure) and the intralobular ducts and then feeding into the extralobular duct which is lined by columnar (rectangular) cells
Breast Cancer
There are two major types of breast cancer. The most common form arises from the ducts and is called ductal cancer (carcinoma) and represents about 80% of breast cancer. The second type is called lobular cancer and it arises from the lobules of the breast.