Pathology - Disorders of Growth Flashcards
What is hyperplasia?
Increase in cell number
May be physiological or pathological
Seen in hormonally sensitive organs such as the endometrium, breast and thyroid
What effect may certain drugs have on gingival tissue?
Hyperplasia
within epithelium and underlying connective tissue
What is hypertrophy?
Increase in cell size
May be physiological or pathological
Often seen in skeletal or cardiac muscle
What is atrophy?
Reduction in cell size and number in an organ than was of normal size.
May be caused by ageing or lack of use/stimulation
What is hypoplasia?
Reduced size of an organ than never fully developed to normal size
Developmental defect
Give an example of hypoplasia
Pulmonary hypoplasia
Which disorders of growth are potentially reversible?
Hyperplasia
Hypertrophy
Atrophy
What is metaplasia?
Acquired form of altered differentiation from one mature cell type to another
Give an example of metaplasia.
Barrett’s oesophagus
What happens if environmental changes leading to metaplasia persist?
Leads to further changes that can manifest as dysplasia and progress to malignancy
How are cells classified according to their population growth pattern?
Labile
Stable
Permanent
What is characteristic of labile cells?
Continuously dividing
e.g. surface epithelia, haematopoetic cells
What is characteristic of stable cells?
Low level of replication, but may divide rapidly if stimulated
e.g. Hepatocytes, fibroblasts, endothelium
What is characteristic of permanent cells?
Non-dividing and unable to re-enter the cell cycle
e.g. neurones, skeletal and cardiac muscle
What factors inhibit apoptosis?
Growth factors
Cell matrix components
Viral proteins
What factors induce apoptosis?
Withdrawal of growth factors
Loss of matrix attachment
Viruses
Free radicals
Ionising radiation
DNA damage
Fas ligand/CD95 interaction
What is p53 protein’s role in cell life?
It induces apoptosis
How can neoplasia be classified?
Behavioural - benign or malignant
Histogenetic
What are the features of benign neoplasia?
Do not metastasise
Well differentiated, resemble normal tissue
Expansile growth with no invasion
Encapsulated
No necrosis
Normal N;C ratio
Minimal pleomorphism
Few and normal mitotic figures
Diploid
Nuclei not hyperchromatic
What is a squamous papilloma?
Usually benign papilloma affecting
skin, lip, oral cavity, tongue, pharynx, larynx
oesophagus, cervix, vagina, anal canal
What are the features of malignant neoplasms?
May metastasis
Invasive growth pattern
Not encapsulated
Variable degree of differentiation
Necrosis
Increased N:C ratio
More frequent and abnormal mitotic figures
Hyperchromatic nuclei
Aneuploid
What is a squamous carcinoma?
Cancer
skin, digestive tract, lungs