L4 - Breast Pathology (Dr Muhammed Sohail) Flashcards
- Classify common diseases of breast - Describe risk factors for breast cancers - Explain different common types of breast cancers and their prognostic and therapeutic significance including the difference between in-situ and invasive tumours. - Understand the different diagnostic tools and treatment modalities for breast cancers - Explain the breast cancer screening program and role of histopathologists in diagnosis and management of breast cancer (119 cards)
What is a breast
a modified sweat glad covered by skin and subcutaneous tissue
How does histology and physiology play into pathology
Histology (tissue structure) and physiology (tissue function) are fundamental to pathology, as pathologists study the structural changes (histopathology) and functional alterations (pathophysiology) in tissues and organs caused by disease “ if you don’t know abnormal than you don’t know what abnormal is” - you have to understand both histology and physiology
what does the breast rest on
Pectoralis muscle from which it is separated by a fascia
What holds the breast upwards
the Cooper’s ligament ( dense connective tissue which extends from the underlying pectoralis fascia to the skin of the breast)
What is the breast divided into (histology of the breast)
two elements ( like any gland) :
1. parenchema, which is the functional part of the gland
2. stroma/ connective tissue, which supports the parenchema
what is the parenchyma divided into
again into two more elements:
1. terminal duct lobular units (TDLU)
2. branching duct system
What is a terminal duct lobular unit (TDLU)
a structural and functional unit of the breast made up of multiple acini grouped together and the terminal duct. it is the primary site for many breast pathologies e.g. fibroadenoma, lobular cancer or invasive ductal carcinoma
Acini vs acinus
- Acinus is the single functional unit of globular tissue, often sac shaped and responsible for secretion e.g. milk during lactation periods and enzymes
- acini is the plural of acinus and refers to clusters of the sac like cells that form the lobule.
Where do secretions made by the acini need to be drained to
the nipple through the terminal duct (ductal system)
What are interlobular ducts
Interlobular ducts are located between the acini lobules. They collect and transport secretions (e.g., milk or enzymes) from smaller ducts within the lobules (intralobular ducts) to a larger lactiferous duct which drains into the nipple
What are interlobular ducts lined by in the breast
by epithelial cells and surrounded by connective tissue
how many terminal duct lobular units are there on each side of the breast
around 15-20
Where is milk stored
in the lactiferous sinus (and then upon suckling it is released onto the nipple)
What are the two cell types that line the entire ductal lobular system
- the inner epithelial cells
- the outer myoepithelial cells
what characteristic gives myoepithelial cells its name
the fact that it has dual characteristics of both muscle and epithelial cells
what is the normal function of myoepithelial cells
to squeeze the secretion forward by contracting (mycin and actin filaments)
how can the outer myoepthlial cells be used to differentiate between in situ and invasive malignancy in pathology
Malignant invasive carcinomas invade the stroma and produce their own basement membrane, which can stain positive for collagen and laminin, potentially mimicking non-invasive tumours. To differentiate, the absence of myoepithelial cells is key, as invasive carcinomas destroy these cells when invading the basement membrane but cannot regenerate myoepithelial cells
what do you do to make sure that the tumour is benign
when you see the two cell types that line the entire ductal lobular system are intact through staining and using various markers … because the inner epithelium and outer myoepithelial layers have distinctive ultrastructural and immunohistochemical characteristics
what are some example markers used to identify myoepithelial cells
SMM, p63 and ck5/6
Why do we classify diseases
helps group diseases with common features, enabling effective communication across disciplines, understanding of their characteristics, and guiding appropriate treatment strategies.
What does it significy if a disease ends with itis
that it is typically an inflammatory disease
what are the classification for inflammatory conditions
- Acute mastitis
- chronic mastitis
- mammary duct ectasia
- fat necrosis
When does acute mastitis occur
During lactation, bacteria accumulate when it isn’t looked after properly.
when does chronic mastitis occur
when acute mastitis isnt dealt with and the inflammation lasts more than two weeks.