1.06 - Neoplasia Flashcards
What does the term tumour mean?
Swelling
Can be non-neoplastic (such as caused by inflammation or infection) or can be neoplastic
What does neoplasm mean?
“New Growth”
A neoplasm is a an abnormal mass of tissue, the growth of which exceeds and is uncontrolled with that of the normal tissues and persists in the same excessive manner after cessation of the stimuli which evoked the changes
Believed that these lesions arise due to the accumulation of somatic mutations.
What does the term oncogenesis mean?
The process of forming a tumour
What do the terms benign and malignant mean?
Bening: “Good natured”. However, benign tumours can, depending on location, cause death.
Malignant: “Very Harmful”
What are some gross features that we can use to distinguish between benign and malignant neoplasms?
Structure Rate of Growth Invasive Growth Disseminated growth by metastasis Of these features, metastasis is a unique feature of malignant neoplasms. Benign neoplasms never metastasise
What are the cytological features of Malignant Cells?
Variable cell size and shape (Cellular Pleomorphism)
Variable nucleus size and shape (Nuclear Pleomorphism)
Increased Nuclear:Cytoplasmic ratio
Hyperchromatic Nuclei
Increased mitosis and abnormal mitosis
Tumour Giant Cells
Do Benign cells differ compared to Malignant cells with respect to the cytological features of malignant cells.
They might show some or all but not to the same extent to that in Malignant cells.
What is Cellular Pleomorphism?
A Cytological feature of malignant cells
Normal cells show uniform size and shape whereas malignant cells vary in their size and shape
What is Nuclear Pleomorphism?
A Cytological feature of malignant cells.
Normal cells have uniform nuclear size and shape whereas malignant nuclei will vary in size and shape
What is Increased Nuclear:Cytoplasmic Ratio?
A Cytological feature of malignant cells
Normal is 1:4-1:6.
Ratio may approach 1:1 in malignant cells
What is Hyperchromatic DNA?
A Cytological feature of malignant cells
Increased intensity of the nuclear stain in malignant cells due to increased DNA
What is Increased and Abnormal Mitosos?
A Cytological feature of malignant cells
The mitotic rate is increased and abnormal in malignant cells compared to normal cells
What are Tumour Giant Cells?
A Cytological feature of malignant cells.
Cells that have duplicated their DNA but have failed to separate completely. A number of cells in one!
Compare Malignant and Benign neoplasms with respect to the arrangement of cell to each other.
Benign - orderly
Malignant - disordered
Compare Malignant and Benign neoplasms with respect to their growth & movement
Benign - tend to grow by expansion and often associated with a capsule
Malignant - tend to infiltrate. “Penetrate with hostile intent”
Define: Differentiation
Extent to which cells resemble normal counterpart (morphologically and functionally)
Can be graded as Well, Moderately or Poor.
Well differentiated: resemble cell of origin
Poorly differentiated: largely different to cell of origin
Define: Anaplasia
Lack of differentiation. i.e. Do not bear any resemblance to the normal cells, whether in structure or function.
Describe the Rate of Growth of Benign and Malignant neoplasms
Benign are slow growing
Malignant are fast growing
Rate of growth correlates with blood supply and differentiation
Fast growing neoplasms may undergo central necrosis due to rapid growth (will appear dark and light on imaging due to the necrosis)
Describe Invasion of Malignant and Benign neoplasms
Invasion is a reliable feature of malignancy
It means neoplastic cells have moved through the basement membrane.
Malignant neoplasms invade and destroy the normal tissue
Malignant neoplasms may appear macroscopically capsulated but microscopically finger like invasion is seen
Benign neoplasms do no invade (they grow by expansion and show a capsule, however lack of a capsule does not always indicate malignancy)
Define: Metastasis
A neoplasm implant discontinuous from the primary neoplasm
Describe Metastasis
Metastasis is an unequivocal sign of malignancy 3 Pathways for metastasis include: - Seeding via body cavities - Lymphatic spread - Haematogenous spread
Sometimes metastasis cannot be explained by the anatomy of the organs involved. e.g. metastasis of lung carcinoma to the adrenal glands or metastasis of neuroblastoma to liver and bones.
Compare Benign and Malignant neoplasms with respect to Differentiation/Anaplasia
Benign: Well differentiated. Structure may be typical of tissue of origin
Malignant: Some lack of differentiation with anaplasia
Compare Benign and Malignant neoplasms with respect to Rate of Growth
Benign: Usually progressive & slow. May come to a standstill or regress. Mitotic figures are rare & normal
Malignant: Rapid. Mitotic figures may be numerous and abnormal
Compare Benign and Malignant neoplasms with respect to Local Invasion
Benign: Usually cohesive & expansive, well demarcated masses that do not invade or infiltrate surrounding normal tissues
Malignant: Locally invasive, infiltrating the surrounding normal tissues. Sometimes may seem cohesive and expansile.
Compare Benign and Malignant neoplasms with respect to Metastasis
Benign: Absent
Malignant: Sometimes present. The larger & less differentiated the primary, the more likely it is to metastasise.
What is the suffix for a benign neoplasm?
-oma
What is a Fibroma?
A benign neoplasm of Fibroblasts
What is an Angioma?
A benign neoplasm of blood vessels
What is a leiomyoma?
A benign neoplasm of smooth muscle
What is a papilloma?
A benign neoplasm with finger-like projections
What is an adenoma?
A benign neoplasm that forms glands or originating from glands
What is a cystadenoma?
A benign neoplasm that forms glands that also has cystic areas
What is papillary cystadenoma?
A benign neoplasm that forms glands, with finger like projections and cystic areas.
What are the exceptions to the -oma rule for benign neoplasms?
Melanoma
Lymphoma
What is the name for a benign neoplasm of fibroblasts?
Fibroma
What is the name for a benign neoplasm of blood vessels?
Angioma
What is the name for a benign neoplasm of smooth muscle?
Leiomyoma
What is the name for a benign neoplasm that has finger-like projections?
Papilloma
What is the name for a benign neoplasm that forms glands?
Adenoma
What are malignant neoplasms of mesenchymal origin called?
Sarcoma
What is a sarcoma?
A malignant neoplasm of mesenchymal origin
What are malignant neoplasms of epithelial origin called?
Carcinoma
What is a carcinoma?
A malignant neoplasm of epithelial origin
What are mixed neoplasms?
Neoplasms that show divergent differentiation.
They can either be benign or malignant.
e.g. Carcinosarcoma
What feature is most important in differentiation a malignant neoplasm from a benign neoplasm?
- Cellular Pleomorphism
- Metastatis
- Mitotic Rate
- Necrosis
- Size
Metastasis
The dest definition for desmoplasia is:
- An in situ carcinoma
- Carcinoma which is confined to the basement membrane
- the induction of a fibrous response by malignant cells
- The heterogeneity of a primary neoplasm
- The ability of tumour specific membrane receptors to localise glycoproteins
The induction of a fibrous response by malignant cells
Which of the following findings is most important for the grading (differentiation) of neoplasms?
- Presence of metastasis
- Size of neoplasm
- Level of invasion
- Microscopic pleomorphism of nuclei and the number of mitosis
- Presence of neoplastic cells in the vascular spaces
Microscopic pleomorphism of nuclei and the number of mitoses.
A benign neoplasm composed of smooth muscle is called a:
- Rhabdomyoma
- Angioma
- Leiomyoma
- Pleomorphic adenoma
- Myxoma
Leiomyoma
A malignant epithelial neoplasm is composed of squamous cells is called:
- Adenocarcinoma
- Squamous cell carcinoma
- Squamous cell sarcoma
- Squamous adenoma
- Adenoma
Squamous Cell Carcinoma
Define: Desmoplasia
Desmoplasia is the growth of fibrous or connective tissue. It may occur around a neoplasm, causing dense fibrosis around the tumour.
