Narrator: ANDI concept of benign breast disease
has been explained in this video animation.
ANDI is an acronym for
Aberration in Normal Development and Involution.
This concept was first initiated
by experts in benign breast disease
at Cardiff Breast Unit,
led by Professor L.E. Hughes,
Robert Mansel and David Webster.
This concept allows us to understand
most of the symptoms and presentation
of patients suffering from benign breast disease.
It is thought that nodularity of the breast,
nipple discharge, mastalgia,
small lumps in the breast like fibroadenoma, duct papilloma,
and breast cysts can all be explained
with this pathophysiological concept of ANDI.
We shall explain this concept through some anatomical facts.
There are seven to eight lobes in each breast,
these are arranged like bunch of grapes.
Each grape representing the milk gland, or acinus,
and the stalk represents the major milk duct
opening at the nipple.
Each lobe contains 10 to 40 lobules,
which in turn are composed of 10 to 100 acini.
These acini are the basic secretary unit of the breast.
The terminal ducts, together with the lobules,
constitute Terminal Ductal Lobular Unit,
known by the acronym TDLU.
TDLU is the most hormone responsive
and most active part of the mammary gland.
The epithelial lining of the ducts and acini
has a luminal and a basal cell layer.
The growth of these cells is controlled
by the hormones estrogen and progesterone.
Estrogen causes development of the ducts and stroma
with fat deposition,
progesterone cause maturation
and branching of the ductal lobular system
primed by the estrogen.
It also causes secretion within the acinus.
Progesterone is also responsible
for retention of water within the breast stroma.
The blood levels of estrogen and progesterone
change with the menstrual cycle.
From day zero of the menstrual cycle
there is a rise in level of estrogen
with formation of Graafian follicle in the follicular phase.
Lobules are quiescent in this phase.
In the post-ovulatory phase
there is a second peak of estrogen
along with rising levels of progesterone from corpus luteum.
These hormones result in proliferation
of cells of the ductal lobular epithelium,
along with increased number of acini.
Moreover, there is increase in the fat and water content
within the breast stroma.
The net result of these changes
is an increase in the breast volume,
compelling some ladies to even change their garment
to a larger size.
The increase in breast volume
causes pressure on the pain nerve endings,
resulting in breast pain or discomfort.
This is called mastalgia.
In some degree this mastalgia
is a normal physiological response.
However, when it becomes severe
and lasts for more than a week,
disturbing the activities of daily life,
we need to consider it as pathological and treat it.
Initially, in most women,
there is a uniform growth of cells throughout the breast.
Later on some cells become hyperresponsive
to the hormones,
resulting in more growth of the ducts
and alveoli in some area, resulting in nodularity.
If you examine a lady with nodularity
in the pre-menstrual phase
you will encounter pea sized, often tender nodules
scattered throughout the breast
with soft and supple breast tissue in between.
Marked growth of ductal lobular cells,
along with stroma in a localized manner
may result in formation of a discreet lump
in the breast, called fibroadenoma.
fibroadenoma is not a true neoplasm
and is now considered as part of ANDI manifestation.
This view is supported by the fact
that some girls experience increased growth of fibroadenoma
in the pre-menstrual phase, and reduction in the size
after the onset of menstrual flow.
Proliferation of the ductal epithelium
leads to ductal hyperplasia,
which may result in increased secretion
presenting as physiological nipple discharge in some ladies.
Localized growth of cells within a dilated duct
leads to a papilloma formation,
it has a central fibrovascular core
and Papillae lined by myoepithelial and luminal cells.
Sometimes the papilloma may undergo infarction
by torsion of the stock,
resulting in bloody nipple discharge.
In the perimenopausal period
involuntary changes with overgrowth
of the fibro connective tissue around the ducts
leads to ductal blockade.
Dilatation and unfolding of the lobules,
along with pent up secretion result in cyst formation.
Initially, microscopic cysts are formed,
many such microscopic cysts may join to form a macro cyst.
Thus, we can appreciate that ANDI concept
enables us to understand the mechanism
of most of the benign breast symptoms,
mainly the breast pain, nodularity,
the change in breast size, nipple discharge,
formation of fibroadenoma, breast cysts and duct papilloma.
Thank you.