92 - Neoplasia 1 Flashcards
Cancer deaths vs cardiovascular deaths in Australia
33% of deaths cardio, 30% are from malignancy per year.
Age group where most cancers are diagnosed
68% in people aged 60 and older.
Proportion of people over 85 diagnosed with cancer
1/2 males, 1/3 females.
Cancers accounting for over 60% of cancers diagnosed
Prostate, colorectal, breast, melanoma of the skin, lung
Most common cancers
Basal cell cancer, squamous cell carcinoma of the skin.
Very rarely lead to death. Not very aggressive.
Most common cancers in Australia
Basal cell cancer, squamous cell carcinoma of the skin.
Very rarely lead to death. Not very aggressive.
Neoplasia
Excessive and unregulated cell proliferation.
Features of neoplasia 1 2 3 4 5
1) Multistep process beginning in a single cell.
2) Aberrant genetic, epigenetic control mechanisms affecting cell cycle, apoptosis, DNA repair
3) Acquire other features that allow neoplastic growth to progress
4) Comprise neoplastic cells and reactive stroma.
5) Can be benign or malignant
Examples of cells in reactive stroma
Inflammatory cells, fibroblasts, blood vessels
Tumour
Any mass lesion. Commonly used to describe neoplastic lesions, but this is very broad.
Characteristics of malignant cells 1 2 3 4 5 6
Sustaining proliferative signalling Evade growth suppressors Activating invasion and angiogenesis Enabling replicative immortality Inducing angiogenesis Resisting cell death
Most common cancers in males and females
Prostate in males, breast in females.
Most common cancers in males and females in Victoria
Prostate in males, breast in females.
Leading causes of cancer death in males and females in Victoria
Lung cancer leading cause in both.
Prostate and breast are second-most.
Who diagnoses a cancer?
A pathologist.
Most common cancer globally
Lung
Why is liver cancer more common globally than in Australia?
Prevalence of hepatitis B and C
Examples of paediatric cancers 1 2 3 4
Certain leukaemias.
Neuroblastomas
Wilm’s tumour
Certain lymphonmas
What can paediatric cancers be referred to as?
Blastomas
Features of benign cells 1 2 3 4
• Local expansile, generally slow growth, often (not always) well circumscribed (+/- encapsulated) • Well differentiated cells • Unable to metastasise • Rarely life threatening
Features of malignant cells 1 2 3 4
- Locally invasive, destructive growth, often (not always) poorly circumscribed
- Frequently induce ‘desmoplasia’ in stroma as they invade
- Sometimes necrosis: from tumour outgrowing blood supply
- Variable differentiation: well, moderate, poor or anaplastic
- Potential to metastasise: spread and grow at a site separate to the primary tumour
Ways in which tumours can metastasise
- Lymphatic
- Haematogenous
- Transcoelomic
Most important features of malignant cells
Invasive, can metastasise
Transcoelomic
Metastasis via body cavities
Features of benign cells 1 2 3 4
- Local expansile, generally slow growth, often (not always) well circumscribed (+/- encapsulated - capsule not v common)
- Well differentiated cells
- Unable to metastasise
- Rarely life threatening
Transcoelomic
Metastasis via body cavities
Features of malignant cells 1 2 3 4
- Locally invasive, destructive growth, often (not always) poorly circumscribed
- Frequently induce ‘desmoplasia’ in stroma as they invade
- Sometimes necrosis: from tumour outgrowing blood supply
- Variable differentiation: well, moderate, poor or anaplastic
- Potential to metastasise: spread and grow at a site separate to the primary tumour
Transcoelomic
Metastasis via body cavities
Uncertain malignant potential/borderline
Neoplastic cells with an appearance betwween benign and malignant.
Often non-aggressive with a slow course, but can metastasise. Uncertain.
EG: In ovary
One of the most common benign lesions
Leiomyoma.
Smooth muscle benign growth in the uterus.
One of the most common benign lesions
Leiomyoma.
Smooth muscle benign growth in the uterus.
Main route of cancer metastasis
Lymphatic.
Move to local lymph nodes. Often grow in the first lymph node in the lymphatic drainage pathway.
Main route of cancer metastasis
Lymphatic.
Move to local lymph nodes. Often grow in the first lymph node in the lymphatic drainage pathway.
Can then get into the blood by draining from the lymph.
Difference between tumour growth and metastasis
Metastasis must be tumour cells growing completely separately from the primary tumour.
Common sites of metastases 1 2 3 4 5
Local lymph nodes Bone Lung Brain Liver
Common sites of metastases 1 2 3 4 5
Local lymph nodes Bone Lung Brain Liver
Common sites of distant metastases
Bone Lung Brain Liver (local lymph node is not considered 'distant')
Common sites of distant metastases
Bone Lung Brain Liver (local lymph node is not considered 'distant')
Name for metastasis in lung where there is a diffuse pattern of malignancies in the lung, from spreading through the lymph
Lymphangitis carcinomatosis
Cytological histopathological appearance of neoplasia 1 2 3 4 5 6
Larger nuclei
Pleomorphic nuclei
Coarser nuclear chromatin
Hyperchromatic nuclei (can be from extra copies of chromosomes, therefore stain more intensely with haemotoxylin)
Larger, more prominent nuclei
More mitotic activity, +/- abnormal mitotic figures.
Mitotic figures
Evidence of cells about to divide
EG: Separate sets of chromosomes
Desmoplastic stroma
Abnormal stroma in benign and malignant neoplastic lesions
Desmoplastic stroma features
Many more fibroblasts, fibroblast proliferation
Many more inflammatory cells
More collagen deposition
Contributes to tumour firmness
What contributes to the firmness of a tumour?
Desmoplastic stroma
How can malignant cell lineage be determined?
Histologically, by looking at the phenotype of the cells. Often resembles that of the cells where malignancy originated
Features of glandular cell-lineage malignancies
1
2
3
Form a lumen.
Signet ring cells
Formation of mucin
Signet ring cells
Cells with mucus within the cells.
Classical of EG: cancers from stomach cells
Features of squamous cell-lineage malignancies 1 2 3 4
Show features of stratified squamous epithelium.
Eosinophilic cytoplasm
Intercellular bridges (spikes of cytoplasm between cells, where desmosomes hold cells together).
Keratinisation.
How does keratinisation appear histologically?
A swirl of anucleate cells (circular)
Features of smooth muscle cell-lineage malignancies
1
2
Elongated nuclei, with rounded ends.
Looks like smooth muscle
Differential diagnosis of a mass lesion
Neoplastic or non-neoplastic?
If neoplastic: Benign or malignant?
Type: mesenchymal, epithelial, etc
If malignant: primary or metastatic?
Differential diagnosis of a mass lesion 1 2 3 4
Neoplastic or non-neoplastic?
If neoplastic: Benign or malignant?
Type: mesenchymal, epithelial, etc
If malignant: primary or metastatic?
Clinical course of action if there is a suspected malignancy
Biopsy
Things that a pathologist looks for in a biopsy of a possible malignancy 1 2 3 4
Cytological features
Architecture +/- necrosis
Stroma
Cell lineage
Prefixes in cancer naming
- Adeno: glandular
- Squamous cell
- Leiomyo: smooth muscle
- Osteo: osteobastic (osteoid forming)
Suffixes in cancer naming
• Benign: -oma
• Malignant:
– Carcinoma: epithelial
– Sarcoma: mesenchymal
Suffixes in cancer naming
• Benign: -oma
• Malignant:
– Carcinoma: epithelial
– Sarcoma: mesenchymal
Seminoma
A malignant testicular lesion (breaks rule of -oma for a benign lesion)
What does the ‘grade’ of a cancer refer to?
Degree of differentiation
Features of well-differentiated lesions
1
2
3
• More closely resemble mature cells
• Less cytologic atypia (smaller more uniform nuclei, inconspicuous nucleoli), less
mitotic activity
• Architecturally more organised
Features of poorly-differentiated lesions
1
2
3
• Poorly resemble mature cells
• More cytologic atypia (enlarged pleomorphic nuclei, prominent nucleoli, nuclear
hyperchromasia or coarse nuclear chromatin), more mitotic activity +/- atypical
mitoses
• Architecturallly less organised
What does the ‘grade’ of a malignant tumour refer to?
Degree of differentiation
Well-differentiated vs poorly-differentiated malignancies
Well-differentiated are less-aggressive than poorly-differentiated (in general)
Example of poorly-differentiated vs well-differentiated malignancies
Well-diff adenocarcinoma will have lumens, as is a glandular cancer. Loses these as it becomes less diff.
Well-diff squamous cell carcinoma has keratinisation.
More atypia in poorly-differentiated nuclei
Example of poorly-differentiated vs well-differentiated malignancies
1
2
3
Well-diff adenocarcinoma will have lumens, as is a glandular cancer. Loses these as it becomes less diff.
Well-diff squamous cell carcinoma has keratinisation.
More atypia in poorly-differentiated nuclei
Which cell types do malignancies arise from?
Potentially adult stem cells.
Which cell types do malignancies arise from?
Potentially adult stem cells.
