Principles or Tumours and Presentations of Malignancy Flashcards
(32 cards)
What is neoplasia and neolpasm?
Cell proliferation occurring in the absence of any continuing external stimuli
A neoplasm is an abnormal mass of tissues which shows uncoordinated growth and serves no useful purpose
Tumour is a synonym for neoplasm that applies to both benign or malignant masses
What is the behaviour and macroscopic appearance of a benign tumour?
- Slow growing
- Well circumscribed
- Encapsulated by a layer of compressed fibrous tissue
- Not locally invasive
- NO METASTATIC POTENTIAL
What is the behaviour and macroscopic features of malignant tumours?
- Fast growing
- Poorly circumscribed
- Non-encapsulated
- INVASIVE GROWTH with destruction of adjacent tissue
- METASTATIC POTENTIAL
How is a malignant tumour defined?
Invasive growth + metastatic potential
What are the microscopic features of benign tumours?
- Very well differentiated
- Cells are uniform throughout tumour
- Few mitoses
- Normal nuclear:cytoplasmic ratio
What are the microscopic features of malignant tumours?
- Variable/poor differentiation
- Cells and nuclei vary in size and shape throughout tumour
- High nuclear:cytoplasmic ratio
What are epithelial cells and the different types of epithelium found in the body?
Cells that line the surfaces of the body
Squamous epithelium => skin and oesophagus
Grandular epithelium => respiratory and GI tract
Urothelium => urinary tract
How are epithelial malignancies named?
Benign epithelial tumours => end in -oma
Malignant epithelial tumours => end in =carcinoma
NOT ALL CELLS ENDING IN -OMA ARE TUMOUR eg. granulomas (aggregation of activated macrophages)
Adenocarcinoma = malignant glandular epithelium
What are the defining features of Adenocarcinoma and Squamous cell carcinoma?
=> Adenocarcinoma:
- Gland formation
- Mucin production
- Nucleas completely displaced to the side in cells
=> Squamous cell carcinoma:
- Keratin formation
- Intercellular bridges between cells
Through what route do carcinomas and adenocarcinomas metastasise?
Carcinomas through the lymphatic system
Adenocarcinomas though the blood
What is grading and staging of tumours?
Grading => aggressiveness of behaviour of a cancer (how differentiated it is)
Staging => extent of anatomical spread
In general, what is the grading system for most tumours?
Grade 1 or well differentiated => less aggressive behaviour
Grade 2 or moderately differentiated => intermediate
Grade 3 or poorly differentiated => more aggressive
What is the grading system specifically for carcinomas?
Most carcinomas graded 1-3
Exceptions:
Renal cell carcinoma - Fuhrman system (4 tier system)
Prostatic carcinoma - Gleason system (5 tier system)
What is the grading system for lymphomas?
Hodgkin’s - not graded
Non Hodgkin’s - Low or high grade
Why is staging important?
Most important prognostic factor of cancer
What system is most commonly used for staging of most cancers and how does it work?
TNM staging
T - Tumour spread
N - Regional lymph node spread
M - Presence of distant metastases
T N and M or put together to give an overall stage of I to IV
How is the T stage determined for primary tumours?
- Cancers arising from a hollow viscus are staged according to how deep they invade the wall of the viscus and whether they invade adjacent structures
- Cancers arising at other sites often staged by measuring their maximum dimension
What are the other staging systems of specific cancers?
FIGO system => Gynacological cancers
ANN ARBOR system => Lymphomas
DUKES system => Colorectal carcinoma
How are the symptoms of cancer categorised?
=> LOCALISED:
- Related to tissue destruction at the site of the cancer
- Eg lung carcinoma would present with cough, haemoptysis and chest wall pain
=> METASTATIC:
- Related to secondary deposits of the cancer in distant organs
=> SYSTEMIC:
- Prolonged fever
- Weight loss
- Loss of appetite
- Decreased immunity
=> Paraneoplastic syndrome:
- Caused by substances produced by the tumour
- Seen in a range of cancers:
Small cell carcinomas - SIADH, ectopic ACTH production, Lambert Eaton Syndrome
Squamous cell carcinomas - Hypercalcaemia, hyperthyroidism, clubbing
Bronchial carcinoma causes excess seratonin release
Large cell carcinoma - B hCG release
What are the common sites of metastases and their presentations?
=> Lung
- Haemoptysis
- Pneumonia
- Pleural effusion
=> Liver
- Jaundice
- Hepatic failure
=> Brain:
- Seizures
- Stroke
=> Bone marrow:
- Pancytopenia (all three cell lines)
- Anaemia
- Leukopenia
- Thrombocytopenia
=> Bone
- Pain
- Fracture
- Spinal cord compression
What is atrophy?
- Reduction in size of a tissue or organ
- May be due to a reduction in cell number or a reduction in cell size or both
What is hyperplasia?
- Increase in cell number
What is hypertrophy?
- Increase in cell size
What is metaplasia?
- When one mature cell type is replaced by another as a way to adapt to the changed environment
- May be physiological or pathological
- It MAY turn into dysplasia, a premalignant phase
