Week 4 - Disorders Of Growth Flashcards
What is neoplasia?
The process by which a neoplasm is formed
What is a tumour?
Tumour = swelling
-used as a synonym for neoplasm
How does a benign tumour grow?
Displaces the adjacent tissue - makes own space
How does a malignant tumour grow?
By infiltration of local tissues and spreads to other parts of the body
What is a primary tumour?
The original malignant tumour
What is a secondary tumour?
“Offspring” of a primary malignant tumour
Often metastases from somewhere else
How do malignant tumours spread?
Local - direct invasion
Distant - metastases
What is metastasis?
the development of secondary malignant growths at a distance from a primary site of cancer
What are the routes of metastasis (common and less common)?
Common:
- lymphatics
- blood
- transcoelomic (through peritoneal cavity)
Less common:
- along epithelial-lined spaces
- within epithelium
How do metastases occur via the lymphatic system?
- tumour may directly invade lymphatics
- tumour emboli filtered out of blood , then grow in lymph nodes (typical of epithelial malignancy -carcinomas)
How do metastases occur via the blood?
- tumour may invade blood vessels
- emboli filtered out by capillary bed e.g. liver, lung
What malignancies often metastasise via the blood?
- stromal malignancy
- later stages of epithelial malignancy
In terms of metastasis what is transcoelomic spread?
- peritoneal, pleural
- travels by body cavities
What cancer often metastasises in epithelial-lined spaces?
-bronchiolo-alveolar carcinoma of the lung
What tumour often metastasises within epithelium?
- paget’s disease of the nipple
- vulva and anus
What do the names given to tumour/neoplasms individual lesions depend on?
- site
- behaviour (benign/malignant)
- histogenesis (cell of origin)
Name some benign epithelial tumours
Adenoma
Papilloma
Cystadenoma
Polyp
What is a polyp?
- benign epithelial tumour
- a mass attached to a surface, which may or may not be a neoplasm
What is an adenoma?
a benign tumour formed from glandular structures in epithelial tissue
What is a papilloma?
a small wart-like growth on the skin or on a mucous membrane, derived from the epidermis and usually benign
What is a cystadenoma?
- type of ovarian cyst that may be formed during an abnormal ovulation process
- very common benign ovarian tumour
Name the three types of malignant tumour
Cancer
Carcinoma
Sarcoma
What is cancer?
Any malignant tumour
What is a carcinoma?
A malignant tumour of epithelial tissue
What is a sarcoma?
A malignant tumour of stromal tissue
What are mesenchymal tumours/neoplasms?
mesenchymal neoplasms generally involve abnormal cellular growth in bone, connective tissue, or the lymph and circulatory systems
-may be benign or malignant
How are mesenchymal tumours named?
-according to the cell type with a suffix
- OMA - if benign
- SARCOMA - if malignant
E.g. Lipoma and liposarcoma (can be exceptions)
What is leukaemia?
- all malignant
- neoplastic proliferation of haematopoietic stem cells (give rise to all the other blood cells through the process of haematopoiesis)
- neoplastic cells spill over into the blood stream
- bone marrow and other blood-forming organs produce increased numbers of immature or abnormal leucocytes, suppressing production of normal blood cells
What is lymphoma?
- malignant proliferation of cells of lymphoid tissue
- cancer of the lymph nodes
What are the two types of lymphoma?
Hodgkin’s disease
Non-hodgkin’s lymphoma
What is Hodgkin’s lymphoma?
- mixture of cells, including Reed-Sternberg cells
- B-lymphocytes start to multiply in an abnormal way and begin to collect in certain parts of the lymphatic system. The affected lymphocytes lose their infection-fighting properties - more vulnerable to infection.
What is non-Hodgkin’s lymphoma?
- lacks the cellular mixture of Hodgkin’s disease
- form of malignant lymphoma distinguished from Hodgkin’s disease only by the absence of binucleate giant cells.
What is the difference between Hodgkin’s and non-Hodgkin’s lymphoma?
- main difference is in the specific lymphocyte each involves
- if the presence of a specific type of abnormal cell - Reed-Sternberg cell is detected = Hodgkin’s
- If Reed-Sternberg cell is not present = non-Hodgkin’s
- tell the difference by examining the cancer cells under a microscope
What is a teratoma?
- arises from totipotential cells (an embryonic cell capable of developing into any variety of body cells)
- producing tissues representing all three germ cell layers
- e.g. Has skin/teeth/hair etc
Where can teratomas occur and are they usually benign or malignant?
Ovary (usually benign)
Testes (usually malignant)
Midline (sequestered primitive cells)
What are precursors of malignancy?
- premalignant conditions
- lesions with an increased risk of the development of invasive tumour
- can be non-neoplastic or neoplastic
Name some non-neoplastic premalignant conditions examples
- chronic inflammation (varicose leg ulcers can lead to skin cancer)
- cirrhosis of the liver (hepatocellular carcinoma)
- chronic ulcerative colitis (adenocarcinoma of LI)
- xeroderma pigmentosum (squamous cell carcinoma of the skin)
Name some neoplastic premalignant conditions examples
- familial polyposis coli (autosomal dominant - hereditary, definitely will get cancer, remove colon early -prevent cancer)
- intra-epithelial neoplasia (nuclear changes of carcinoma, without breaching basement membrane - “dysplasia” or “carcinoma in-situ” - important in uterine, cervix, vulva, bronchus etc)
What is tumour grading?
How bad it looks
What is tumour staging?
How far it’s got/has spread
How is a tumour graded?
- assessment of the degree of differentiation of a tumour
- correlates with how aggressive the tumour behaves
- only relevant for malignant tumours
- usually define 3 or 4 grades
What are the problems with tumour grading?
- very subjective
- poor reproducibility
- appears to vary from area to area within most tumours
- need different criteria for each histogenesis
- only modest predictor of outcome
How is a tumour staged?
Based on 3 main features:
- size of primary tumour
- extent of lymph node disease
- any blood-borne metastasis
What is tumour staging sometimes quoted as?
TNM
Describe the TNM system and what it’s used for
staging tumours
T = size of tumour (T1 to T4) N = extent of lymph node involvement (N0 to N3) M = distant metastasis (M0 to M1)
- criteria different for each tumour
- better prediction of outcome than grade for most tumours
What are the effects of tumours?
- displacement or destruction of normal structures
- excess “normal” function
- paraneoplastic phenomena
Name some effects of benign tumours
- mechanical pressure
- obstruction
- ulceration
- infarction of pedunculated tumour
- infection
- rupture of cystic neoplasm
- hormone production
- malignant change
What benign tumour may cause mechanical pressure?
- meningioma compressing the brain
- ovarian cystadenoma compressing ureter
What benign tumour may cause obstruction?
- atrial myxoma
- leiomyoma in GIT
What benign tumour may cause ulceration?
-mucosa over gastric leiomyoma
What benign tumour may cause infarction of a pedunculated tumour?
-subserosal leiomyoma of uterus
What benign tumour may cause infection?
Bladder papilloma
What benign tumour may cause a rupture of cystic neoplasm?
Mucinous cystadenoma of appendix causing pseudomyxoma peritonei
What benign tumour may cause hormone production?
Islet cell tumour of pancreas
Name some effects of malignant tumours
- all the physical effects of benign tumours
- tissue destruction
- haemorrhage
- secondary infection
- cachexia
- pain
- anaemia
- paraneoplastic syndromes
What malignant tumour may cause tissue destruction?
- cancer of the cervix infiltrating ureter
- cancer of the stomach infiltrating pancreas
What malignant tumour may cause haemorrhage?
Any cancer breaching a vessel wall
What malignant tumour may cause secondary infection?
Bacterial invasion of necrotic tumour
What is secondary infection?
An infection that occurs during or after treatment of another pre-existing infection
What is cachexia?
Severe weight loss, increased metabolic rate, tissue necrosis factor etc
What result of a malignant tumour may cause anaemia?
- haemorrhage
- bone marrow replacement
- haemolysis
What are paraneoplastic syndromes?
Paraneoplastic syndromes are symptoms that occur at sites distant from a tumor or its metastasis
Name some paraneoplastic syndromes
- ectopic hormone production
- peripheral neuropathy, cerebellar degeneration, myopathy
- thrombophlebitis migrans
- acanthosis nigricans
- nephrotic syndrome
- finger clubbing
- hypertrophic pulmonary osteoarthropathy
- non-bacterial thrombotic endocarditis
What cancer may cause ectopic hormone production?
- carcinoma of bronchus may cause Cushing’s syndrome, inappropriate ADH secretion, secretion of PTH analogue
- fibrosarcoma can produce hypoglycaemia
- renal carcinoma can release erythropoietin
What is thrombophlebitis migrans and what can it be cause by?
- paraneoplastic syndrome
- Thrombophlebitis is phlebitis (vein inflammation) related to a thrombus (blood clot). When it occurs repeatedly in different locations, it is known as “Thrombophlebitis migrans”
- carcinoma of bronchus (5%) and pancreas (30%)
What is acanthosis nigricans and what can it be caused by?
- paraneoplastic syndrome
- skin appears darkened/black/thickened - esp. under arms/nape of neck
- caused by epidermal growth factor analogue
What is nephrotic syndrome and what can it be caused by?
- paraneoplastic syndrome
- kidney disease, especially when characterized by oedema and the loss of protein from the plasma into the urine due to increased glomerular permeability
- proteinuria, hypoalbuminaemia, generalised oedema
- complexes of tumour antigen and host antibody deposited in glomerulus
What is finger clubbing?
- paraneoplastic syndrome
- thickening of the fingertips that gives them an abnormal rounded appearance
-
What is hypertrophic pulmonary osteoarthropathy?
- paraneoplastic syndrome
- medical condition combining clubbing and periostitis (inflammation of the membrane enveloping a bone) of the small hand joints, especially the distal interphalangeal joints
What is non-bacterial thrombotic endocarditis?
- paraneoplastic syndrome
- form of endocarditis in which small sterile vegetations are deposited on the valve leaflets.
What is a neoplasm?
Abnormal mass of tissue, the growth which exceeds and is uncoordinated with that of normal tissues, and which persists in the same excessive manner after cessation of the stimuli which evoked the change