CANCER 1 Flashcards
(25 cards)
Neoplasia: DEF
Literally means “new growth”; it is the process by which abnormal, uncontrolled proliferation of cells forms a neoplasm or tumour.
Tumour: DEF
A general term referring to a swelling or mass, which may be benign or malignant.
Dysplasia: DEF
Disordered cellular growth, particularly in epithelial tissues, characterized by architectural disorganization and cytological atypia. It may regress or progress to carcinoma.
Anaplasia: DEF
A lack of differentiation seen in malignant tumours; cells show marked pleomorphism, abnormal mitotic figures, and loss of tissue structure.
Metaplasia: DEF
A reversible process where one differentiated adult cell type is replaced by another, often in response to chronic irritation (e.g., Barrett’s oesophagus in acid reflux).
Describe the macroscopic differences between benign and malignant tumours.
Macroscopic Differences:
Benign Tumours:
Well-circumscribed, often encapsulated
Uniform cut surface
Do not invade surrounding tissues
Malignant Tumours:
Irregular margins, poorly demarcated
Infiltrative, finger-like projections
May show areas of necrosis and haemorrhage
Describe the microscopic differences between benign and malignant tumours.
Microscopic Differences:
Benign Tumours:
Cells resemble tissue of origin (well-differentiated)
Low mitotic activity
Normal nuclear morphology
Malignant Tumours:
Varying differentiation; may be anaplastic
High mitotic rate with abnormal mitoses
Pleomorphic nuclei, increased N:C ratio, architectural disorder
- What is the significance of tumour stroma in cancer progression?
The tumour stroma, although non-neoplastic, plays a vital role in cancer development and progression. It includes connective tissue, blood vessels, and inflammatory cells. While it was previously considered inert, current evidence shows that the stroma can either suppress or promote tumour growth. It influences tumour behaviour by supporting angiogenesis, modulating immune responses, and enabling invasive and metastatic properties. A specific type of reactive stroma, desmoplasia, is often seen in aggressive tumours like pancreatic adenocarcinoma.
- Explain the process of carcinogenesis with reference to the colon cancer model.
Carcinogenesis is a multistep process where a normal cell acquires genetic mutations that confer growth advantages, leading to clonal expansion and further genetic instability. The colon cancer model (Vogelstein model) illustrates this progression:
Initial mutation in the APC gene leads to early adenoma.
Followed by KRAS activation → intermediate adenoma.
Loss of tumour suppressors like p53 and additional mutations result in late adenoma and carcinoma.
Tumour progresses from dysplasia to neoplasia, accumulating mutations that promote proliferation, invasion, and metastasis.
This model exemplifies how cumulative genetic alterations drive malignant transformation.
Discuss the clinical implications of benign tumours in confined anatomical spaces.
While benign tumours do not metastasize or invade adjacent tissues, their growth in confined anatomical spaces can have serious clinical consequences. For example:
A schwannoma of the 8th cranial nerve (vestibular schwannoma) can cause hearing loss, tinnitus, and raised intracranial pressure due to compression.
A fibroid (leiomyoma) in the uterus may lead to heavy menstrual bleeding, pain, or complications in pregnancy despite being benign.
A pituitary adenoma can compress the optic chiasm, leading to visual disturbances.
Thus, even benign tumours can require intervention due to mass effect or interference with vital structures.
Which of the following is not typically a benign tumour based on naming conventions?
A. Lipoma
B. Adenoma
C. Melanoma
D. Schwannoma
Correct Answer: C. Melanoma
Which statement best characterizes anaplastic tumours?
A. Composed of well-differentiated cells
B. Show minimal mitotic activity
C. Exhibit high nuclear pleomorphism and loss of polarity
D. Retain their tissue of origin features
Correct Answer: C. Exhibit high nuclear pleomorphism and loss of polarity
What is the correct diagnosis for a well-circumscribed tumour compressing the 8th cranial nerve causing hearing loss?
A. Glioblastoma
B. Metastatic adenocarcinoma
C. Oligodendroglioma
D. Schwannoma
Correct Answer: D. Schwannoma
Metaplasia in the lower esophagus due to chronic acid exposure is called:
A. Dysplasia
B. Barrett’s esophagus
C. Anaplasia
D. Teratoma
Correct Answer: B. Barrett’s esophagus
Which of the following is true about hamartomas?
A. They are malignant lesions
B. They represent metastatic spread
C. They are disorganized tissue native to the site
D. They arise from totipotent germ cells
Correct Answer: C. They are disorganized tissue native to the site
Case-Based
A 35-year-old woman presents with a slowly enlarging lump in her breast. Imaging reveals a well-circumscribed, mobile mass. Histology shows uniform glandular structures. What is the most likely diagnosis?
Answer: Fibroadenoma (benign breast tumour)
case based
A biopsy of a skin lesion shows asymmetry, irregular borders, and variable pigmentation. What is the likely diagnosis?
Answer: Malignant melanoma
Q: What are the two main components of a tumour?
A: Parenchyma (neoplastic cells) and stroma (non-neoplastic support tissue)Q: What does the suffix “-oma” usually indicate?
Q: What does the suffix “-oma” usually indicate?
A: A benign tumour (with notable exceptions like lymphoma, melanoma, glioma)
Q: How can benign and malignant tumours be differentiated microscopically?
A: Benign tumours have well-differentiated cells, low mitotic activity; malignant tumours may show anaplasia, high mitoses, loss of architecture
Q: What is desmoplasia?
A: A fibrous or collagenous response around a tumour, often seen in malignancy
Q: What is the hallmark microscopic feature of anaplastic tumours?
A: Nuclear pleomorphism, abnormal mitotic figures, loss of cell polarity
Q: Define dysplasia.
A: Disordered growth, often of epithelial cells, that can precede cancer
Q: What tumour shows elements from multiple germ layers?
A: Teratoma
