Lecture 1 Flashcards
(23 cards)
What is a disease?
Consequence of failed homeostasis with consequent morphological and functional disturbances
What is pathology?
Study of disease and cellular dysfunction. The opposite of biology
What discipline of pathology does autopsies?
Cellular pathology which encompasses histopathology and cytopathology
What are the pathology disciplines?
Chemical (errors of metabolism etc)
Haematology
Cellular (histo and cyto)
Immunology
Medical microbiology
Importance of microscopic diagnosis?
To remove a lesion in major surgery microscopic diagnosis is required
Histology vs cytology
Histology uses solid samples like core biopsies and skin lesions whereas cytology uses individual cells such as urine, cervical smears and effusions
Histology is more expensive and takes longer but is better for making diagnosis. Cytology cheaper and quicker but generally used to confirm or exclude conditions rather than make a diagnosis
What is distension?
Enlargement or ballooning effect
What is an adrenal mass?
A lump of tissue in the organs close to the uterus eg ovaries
What is ascites?
Abnormal fluid accumulation in the abdominal or peritoneal cavity
What can you look out for to see if cells are abnormal?
Enlarged nucleus
Multiple nucleoli
Histological evidence of a malignant cell?
Enlarged cell
Enlarged nucleus:cytoplasm ratio
Hyperchromatism- increased darkness
Many nuclei- seen as dots
Variability in size and shape of nuclei
Mercedes Benz sign= mitosis figure
What is neoplasia?
Abnormal growth of cells
How does a histopathology at arrive at a diagnosis?
Is this normal or not?
Is this benign or malignant?
Is this inflammatory or neoplastic?
Is this a primary tumour or a metastasis?
What can histopathologists tell us about cancer?
Type eg numerous types of lungs cancers all requiring different treatment
Grade eg poorly, moderately or well differentiated. Poorly differentiated hardest to treat as furthest from parent tissue
Stage- SNM used referring to degree of spread, number of nodes affected and metastasis
Can also provide frozen sections
Eneumonic for cancer stage?
T tumour
N nodes
M metastasis
What is the function of a fixative in histopathology?
To prevent autolysis (self digestion of the tissue)
How big should your tissue sample be?
About the size of a stamp
How do you get tissue hard enough to cut thin slices?
Use paraffin wax
How are thin sections cut?
Microtome
How are tissues stained?
Haemotoxylin and eosin.
Haemotoxylin stains nuclei purple while eosin stains cytoplasm and connective tissue pink
How does immunohistochemistry work?
Specimens that are antigenic (have antigens) are targeted with antibodies which label them for viewing. Actin is an example
What is molecular pathology?
Studies how diseases are caused by alterations in normal cellular molecular biology eg altered DNA, RNA or protein
Eg FISH fluorescence in situ hybridisation used to identify extra HER 2 gene in breast cancer
Frozen sections?
Used during surgery take about 10 mins but artefacts common and so is miss diagnosis
