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Questions and Answers
Which characteristic is not associated with neoplasms?
Which characteristic is not associated with neoplasms?
What type of genetic mutation is not commonly associated with tumor cells?
What type of genetic mutation is not commonly associated with tumor cells?
Which of the following statements regarding hereditary cancers is accurate?
Which of the following statements regarding hereditary cancers is accurate?
Which abnormality primarily leads to overexpression of oncogenes?
Which abnormality primarily leads to overexpression of oncogenes?
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What describes the type of cancer cases that generally show a higher familial link?
What describes the type of cancer cases that generally show a higher familial link?
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Which mechanism is primarily associated with the silencing of tumor suppressor genes?
Which mechanism is primarily associated with the silencing of tumor suppressor genes?
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Which factor does not significantly impact the epidemiology of cancer?
Which factor does not significantly impact the epidemiology of cancer?
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Which statement about preneoplastic disorders is true?
Which statement about preneoplastic disorders is true?
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Which of the following is least likely to contribute to malignancy?
Which of the following is least likely to contribute to malignancy?
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Which is a characteristic of benign tumors compared to malignant tumors?
Which is a characteristic of benign tumors compared to malignant tumors?
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What is true about tumor suppressor genes in relation to tumor development?
What is true about tumor suppressor genes in relation to tumor development?
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Which characteristic is NOT typical of benign tumors?
Which characteristic is NOT typical of benign tumors?
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Which of the following is a type of benign tumor according to nomenclature?
Which of the following is a type of benign tumor according to nomenclature?
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Which of the following describes a malignant tumor characteristic?
Which of the following describes a malignant tumor characteristic?
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What correspondence does the suffix '-oma' typically indicate in tumor nomenclature?
What correspondence does the suffix '-oma' typically indicate in tumor nomenclature?
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Which acquired preneoplastic disorder is associated with long-standing inflammatory conditions?
Which acquired preneoplastic disorder is associated with long-standing inflammatory conditions?
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What term is used to describe a mass that projects above the mucosal surface?
What term is used to describe a mass that projects above the mucosal surface?
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Which statement correctly describes the behavior of malignant tumors compared to benign tumors?
Which statement correctly describes the behavior of malignant tumors compared to benign tumors?
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What feature distinguishes dysplastic changes from hyperplastic changes?
What feature distinguishes dysplastic changes from hyperplastic changes?
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What is a defining feature of hyperchromasia in malignant tumors?
What is a defining feature of hyperchromasia in malignant tumors?
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What is the first step in the ability of tumor cells to invade tissues?
What is the first step in the ability of tumor cells to invade tissues?
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Which of the following factors is NOT related to the mechanisms of local and distant spread of tumors?
Which of the following factors is NOT related to the mechanisms of local and distant spread of tumors?
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Which step is involved in the degradation of ECM during tumor invasion?
Which step is involved in the degradation of ECM during tumor invasion?
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What role does hypoxia play in tumor growth?
What role does hypoxia play in tumor growth?
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What is meant by 'extravasation' in the context of tumor spread?
What is meant by 'extravasation' in the context of tumor spread?
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Which of the following describes a hallmark of malignancy related to the invasion of tissues?
Which of the following describes a hallmark of malignancy related to the invasion of tissues?
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What is the primary action of metalloproteinases in tumor invasion?
What is the primary action of metalloproteinases in tumor invasion?
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Which process is NOT a characteristic of vascular dissemination in tumor spread?
Which process is NOT a characteristic of vascular dissemination in tumor spread?
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What happens to E-cadherins during the early stages of tumor invasion?
What happens to E-cadherins during the early stages of tumor invasion?
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What is the significance of the balance between angiogenic and antiangiogenic factors in tumor growth?
What is the significance of the balance between angiogenic and antiangiogenic factors in tumor growth?
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Which type of tumors primarily arise from epithelial tissue?
Which type of tumors primarily arise from epithelial tissue?
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What is a key difference between benign and malignant tumors in terms of growth?
What is a key difference between benign and malignant tumors in terms of growth?
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Which of the following characteristics is typical of malignant tumors?
Which of the following characteristics is typical of malignant tumors?
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What role do proteolytic enzymes play in tumor progression?
What role do proteolytic enzymes play in tumor progression?
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Which sampling approach is used specifically for identifying the cellular composition of tumors?
Which sampling approach is used specifically for identifying the cellular composition of tumors?
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In tumor classification, what is meant by 'organ tropism'?
In tumor classification, what is meant by 'organ tropism'?
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What is the significance of tumor markers like PSA in medical diagnostics?
What is the significance of tumor markers like PSA in medical diagnostics?
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What primarily characterizes a teratoma?
What primarily characterizes a teratoma?
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Why do certain tumors often arrest in the first capillary bed they encounter?
Why do certain tumors often arrest in the first capillary bed they encounter?
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What is commonly observed with malignant tumors regarding their histological characteristics?
What is commonly observed with malignant tumors regarding their histological characteristics?
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Study Notes
Neoplasia
- A new growth or abnormal outgrowing mass of tissue that does not coordinate with normal tissue.
- Characterized by continued replication, competition for metabolic needs, autonomy in growth despite environment, and reliance on endocrine signals.
Epidemiology of Cancer
- Incidence varies by age, race, geography, and genetics.
- Most prevalent at the extremes of age.
- Geographic variations often attributed to environmental exposures.
- Most cancers are sporadic, but some are familial.
- Familial cancers may be autosomal dominant or autosomal recessive.
- Autosomal dominant cancers are linked to germline mutations of cancer suppressor genes, while autosomal recessive cancers are associated with DNA repair defects.
- Familial cancers are often bilateral and develop earlier than sporadic counterparts.
- Preneoplastic disorders (e.g., skin ulcer, hepatic cirrhosis, endometrial hyperplasia, chronic gastritis) are associated with increased cancer risk.
Genetic Lesions in Cancer
- Tumor cells acquire mutations through point mutations and non-random chromosomal abnormalities.
- Balanced translocations lead to oncogene overexpression or fusion proteins with altered signaling.
- Deletions frequently affect tumor suppressor genes, while gene amplification increases oncogene expression.
- Overexpression of miRNAs can downregulate tumor suppressors, while their deletion/loss leads to proto-oncogene overexpression.
- Epigenetic changes (methylation) can silence tumor suppressor genes and DNA repair genes.
Insensitivity to Growth Inhibitory Signals
- Tumor suppressor genes encode proteins that regulate the cell cycle, halting proliferation.
- Both copies of the gene must be dysfunctional for tumor development.
- Inherited defective copies of tumor suppressor genes contribute to familial predisposition.
- Sporadic cases involve loss of both copies through somatic mutations.
Tumour Types
- Benign: Localized growth, non-spreading, with potential local effects.
- Malignant: Invasive growth, capable of destroying adjacent structures and spreading to distant sites (metastasis).
Benign Tumour Characteristics
- Resemble normal cells of origin in morphology and function.
- Well-differentiated cells.
- Low mitotic activity with normal configuration.
- Slow growth, localized, non-infiltrative.
Acquired Preneoplastic Disorders
- Persistent regenerative cell replication (e.g., skin ulcer, hepatic cirrhosis).
- Hyperplastic and dysplastic proliferations (e.g., endometrial hyperplasia, bronchial dysplastic changes).
- Chronic atrophic gastritis, chronic ulcerative colitis, oral leukoplakia, villous adenomas of the colon.
Benign Tumour Nomenclature
- Cell type of origin + "-oma" suffix (e.g., fibroma, chondroma, leiomyoma).
- Specific names based on cell of origin:
- Adenoma: Glandular pattern.
- Papilloma: Epithelial surfaces, finger-like structures.
- Polyp: Mass projecting above the mucosal surface.
- Cystadenomas: Hollow cystic masses (e.g., ovary).
- Fibroadenoma: Mixed type (e.g., breast, salivary glands).
Malignant Tumour Characteristics
- Pleomorphism: Variation in size and shape.
- Hyperchromasia: Increased nuclear pigmentation.
- High nuclear/ cytoplasmic (N/C) ratio.
- Giant cells: Multiple nuclei.
- Nuclear pleomorphism: Coarse, clumped chromatin.
- Numerous atypical mitoses.
- Loss of polarity: Lack of organized orientation.
- Dysplasia: Uniformity and architectural orientation loss (carcinoma in situ).
- Rapid growth with infiltration, invasion, and destruction of surrounding tissue.
- Metastasis: Secondary implants discontinuous with the primary tumor.
Metastasis Pathways
- Seeding within body cavities.
- Lymphatic spread (carcinomas).
- Hematogenous spread (sarcomas, carcinomas).
- Liver and lungs are common secondary sites.
Mechanisms of Local and Distant Spread
-
Invasion of ECM:
- Detachment of tumour cells from each other.
- Attachment of tumour cells to matrix components.
- Degradation of ECM by proteases (metalloproteinases).
- Cell migration driven by cytokines, matrix cleavage products, and growth factors.
-
Vascular Dissemination:
- Intravasation: Degradation of blood vessel basement membrane, forming tumour emboli.
- Extravasation: Adhesion to endothelium, transgression through basement membrane.
Development of Sustained Angiogenesis
- Vascularization is vital for tumor growth.
- Regulated by angiogenic and antiangiogenic factors from tumor and stromal cells.
- Hypoxia triggers angiogenesis through HIF-1α and VEGF.
- Other factors regulate angiogenesis (e.g., p53 inhibiting angiogenesis).
Tissue Invasion (Hallmarks of Malignancy)
- Loosening of cell-cell contacts.
- ECM degradation by proteolytic enzymes (MMPs).
- Attachment to new ECM components.
- Tumor cell migration.
- Loss of E-cadherin function.
- Release of growth factors and chemotactic/angiogenic fragments.
- Metastatic site prediction based on primary tumor location.
Malignant Tumor Nomenclature
- Mesenchymal origin: Sarcomas (e.g., fibrosarcoma, chondrosarcoma, leiomyosarcoma).
- Epithelial origin: Carcinomas (e.g., squamous cell carcinoma, adenocarcinoma).
- Two components (mesenchymal and epithelial): Teratomas (differentiated into all embryonic layers, benign or malignant, common in ovaries and testicles).
Distinguishing Benign and Malignant Tumors
- Differentiation: Benign tumors resemble tissue of origin (well-differentiated), while malignant tumors are poorly differentiated (anaplastic).
- Growth Rate: Benign tumors grow slowly, while malignant tumors grow faster.
- Local Invasiveness: Benign tumors are well-circumscribed with a capsule, while malignant tumors invade surrounding tissues.
- Distant Spread: Benign tumors remain localized, while malignant tumors metastasize.
Laboratory Diagnosis of Cancer
- Sampling approaches: Excision, biopsy, fine-needle aspiration, cytologic smears.
- Immunohistochemistry and Flow cytometry: Identify protein expression patterns for diagnosis and classification.
- Tumor Markers: Proteins released into serum (e.g., PSA), used for screening and monitoring recurrence.
- Molecular Analyses: Diagnose, predict prognosis, detect minimal residual disease, and diagnose hereditary predisposition.
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Description
Explore the concepts of neoplasia, a condition characterized by abnormal tissue growth and its implications on cancer. This quiz covers epidemiological factors influencing cancer incidence, genetic predispositions, and the characteristics of familial cancers. Test your knowledge on how these factors interact with environmental exposures.
