Objectives:
Breast cancer doesn’t start in the skin of the breast, the
fat surrounding the breast tissue or the fibrous supporting structures of the
breast. Breast cancer begins with the cellular lining in the breast ducts.
Cancers, all cancers, are cellular diseases. Cancer starts when the normal cell divides abnormally, becomes atypical, starts dividing eccentrically, refuses to die when the body tells it to, begins to affect the surrounding cells and, finally, the cell becomes malignant and begins to feed off healthy cells turning them malignant. These sick cells finally become a malignant tumor and the nasty business continues.
Before or just after the changing cells become malignant many of these erratic malformed cells crowd each other out, deprive each other of oxygen and, basically kill each other off. Some of these dead cells calcify and gather is small clumps or lines. If we are lucky and skilled we can image a cluster of these dead cells and thus identify an early cancerous process before any symptom or sign is present.
The Journey down the malignancy trail:
Step one, begins with a healthy terminal duct containing a
thick continuous basement layer of cells lined with a homogeneous layer of
identical epithelial cells each enclosing a single vigorous nucleus.
Step two in the journey is normal hyperplasia. Hyperplasia
is a normal effect of aging. As we age, the conventional ‘die trigger’ in the
cells slows down and our characteristic epithelial cell layer begins to build
up on itself. The cells still represent identical vigorous cells containing
healthy nuclei.
Step three along the path to breast cancer is atypical
hyperplasia. Atypical hyperplasia is considered a pre-cancerous condition. The
rapidly building hyperplasic cells begin to deteriorate. The walls of the cells
become misshapen. The nuclei commence to look deformed. During this stage in
the dark excursion the basement layer of cells remain intact and
characteristic. At this step the dead cells are crowded together and sometimes
the little dead cell bodies calcify. If this happens it is good because the
tiny clusters of calcifications that represent the dead cells inside the duct
can lead us to a burgeoning problem.
Step four is ductal carcinoma in-situ or DCIS.
Step four crosses the line from ‘atypical’ to cancerous. DCIS is the earliest
stage of breast cancer and the most advantageous to find. At some stage in the
atypia process one or a cluster of uncharacteristic cells become cancerous
cells. We have no idea why this occurs, but when it does the process begins to
intensify. The malignant cells rapidly collect healthy cells and alter their
structure into cancer. These malignant cells begin to form a lesion or mass
within the duct. This mass begins to elongate the duct, thin and stretch the
basement cell layer. The malignant process tends to create a virtual graveyard
of dead cells and, if we are lucky, these cells will calcify and we will be
able to pick them up on a mammogram.
Step five is infiltrating ductal carcinoma. By
this stage in the grim excursion the malignant cluster of cells have broken out
of the basement membrane of the duct and has begun to collect breast
parenchymal tissue as food for the tumor. Infiltrating ductal carcinoma very
often is seen as an ill-defined mass containing malignant type calcifications.
Left undetected, infiltrating ductal breast cancer will become a large,
palpable stellate mass which often represents a well established metastasized
breast cancer.
Summary:
The whole point of high quality mammography screening is to
find early signs of breast cancer. Our job is to create the best images we can
using all the knowledge we possess about the disease we are trying to discover.
Know your enemy, know where it hides, know how it grows and
know how to corner it.
Keep up the good fight.
Posts
