Lesson 11 Flashcards
(36 cards)
What is neoplasia?
An abnormality of cellular differentiation, maturation, and control of
growth
What are general rules regarding neoplasms?
- Neoplasms are benign/malignant depending on several features.
- The ability of malignant neoplasms to spread from site of origin
- Benign neoplasms grow but remain localised
What are the hallmarks of malignancy?
Sustaining proliferative signalling Evading growth suppressors Activating invasion and metastasis Enabling replicative immortality Inducing angiogenesis Resisting cell death
What are some common features of tumour cells when looked at under a microscope?
Large, variable shaped nuclei
Many dividing cells, disorganised arrangement
Variation in size and shape
Loss of normal features
What are two different classification of effects of neoplasm?
Local effects
Systemic effects
What are local effects of neoplasm?
Mechanical pressure or obstruction Tissue destruction Non-metastatic hypercalcaemia Haemorrhage Infection
What is mechanical pressure or obstruction and what are some examples?
Depends on tumour site/size
Very common
GI tract obstruction and intussusception
Jaundice
Raised intercranial pressure
Renal failure
What is intussusception?
a serious condition in which part of the intestine slides into an adjacent part of the intestine
Describe GI tract obstruction and intussception
- Bowel obstruction - more common than intussusception
- Small bowel - more common than large bowel
- Desmoplastic reaction – fibrous tissue response (adhesions)
- CT scan
- Urgent operation
Describe jaundice?
• Head of pancreas or CBD (cortico-basal degradation)
• Dilatation of the biliary system
above obstruction
• Often dilatation of gall bladder
What is Corticobasal degeneration (CBD) caused by?
increasing numbers of brain cells becoming damaged or dying over time
Describe raised intracranial pressure?
- Skull is a fixed volume/size inside
- Any growing mass will increase pressure in the skull
- Meningioma, though benign, can be fatal as a result
Describe non-metastatic hypercalcaemia
- Hypercalcaemia without secondary tumour being present in the skeleton
- Ectopic hormone production lung and kidney - PTHRP
- Prostaglandin production
- TNF
Describe haemorrhage
- Epithelial ulcers bleed
- Ulceration of GI tract can cause life-threatening haemorrhage
- Chronic – microcytic anaemia - iron deficiency
- Mechanism: Increased tumour vascularisation (angiogenesis), thin walled vessels and tumour necrosis
Describe infection
- Common in malignancy
- Local or systemic
- Local – drainage blocked, retained secretions
- Neoplastic B-cell proliferation eg. in lymphomas and CLL causes decline in antibody response
- Hodgkin’s lymphoma we see a defective immune response (mycobacteria, viruses, fungi)
- Iatrogenic defective immune response
What are examples of systemic effects?
- Pyrexia
- Cachexia
- Immune system
- Haematological effects
- Endocrine effects
- Bone and soft tissue (non-metastatic)
- Nerve and muscle (non-metastatic)
- Skin
Explain pyrexia
- Common in malignancy
- Especially lymphomas and leukaemias
- Also disseminated carcinomas
- Cytokines - IL-1, TNFα
What is cachexia?
- Definition – Marked weight loss and tissue wasting, notably muscle
- Associated with later stages of malignant neoplasms
- Factors adding to the process are anorexia, malabsorption, release of substances from the neoplasm (possibly TNF)
Explain the immune system?
- Decreased phagocyte activity
- Bone marrow suppression
- Humoral and cellular systems affected • Iatrogenic effect
- Autoimmunity: autoantibodies
- Immune complex formation
Describe haematological effects?
• Anaemia: iron deficiency (microcytic) folate deficiency (macrocytic) autoimmune haemolytic anaemia (autoantibodies) decreased erythropoietin secretion • Increased red cell production • Effect on platelets and clotting
Explain increased red cell production
• Increase in red cell mass • Commonest in: Renal adenocarcinoma Uterine fibroleiomyoma Liver cell carcinoma • Can occur in other neoplasms • Possibly ectopic erythropoietin production
Explain platelets and clotting
- Thrombocytopenic purpura – decrease in platelet count
- Conversely, an increased risk of clots
- Recurrent migratory thrombophlebitis - bronchus, pancreas, stomach, female genital tract
What are endocrine effects of neoplasms?
• Appropriate hormone production
e.g. Pituitary adenoma producing growth hormone, ACTH or
prolactin
Parathyroid adenoma producing parathyroid hormone
• Ectopic hormone production (Paraendocrine syndromes) e.g. Bronchial and pancreatic carcinoma causing ACTH production
Bronchus, kidney, liver, and adrenal neoplasms producing PTH
What is clubbing?
Most severe form - periosteum over terminal phalanges, wrists + ankles thickens + new bone formed from stem cells in periosteum (called hypertrophic pulmonary osteoarthropathy)
HPO is commonest in pleural mesothelioma, less so in small-cell bronchial ca
