MLT GlobeBasic Pathology: Neoplasia – page 4
120 Basic Pathology MCQs on Neoplasia with answers and explanations.
Substances such as benzene, aflatoxin B1 and vinyl chloride, which can induce malignant tumours, are collectively called:
Carcinogens are agents that cause cancer, usually by damaging DNA. Oncogenes and tumour suppressor genes are cellular genes, and restriction enzymes are bacterial DNA-cutting tools.
At the cellular level, cancer growth reflects:
Cancer cells divide mitotically without normal growth control because oncogene activation and tumour suppressor loss disable checkpoints. Meiosis occurs only in germ cells.
Which lesion is a benign proliferation of melanocytes in the skin?
A melanocytic naevus (mole) is a common benign melanocytic neoplasm. Melanoma is its malignant counterpart despite the -oma ending; basal cell carcinoma arises from keratinocytes.
A tumour whose gross and microscopic features suggest it will stay localised and can be cured by local excision is classified as:
Benign tumours are localised, do not invade or metastasise, and are generally curable by surgical excision. Carcinomas and sarcomas are malignant.
A woman in her thirties has bilateral milky breast secretion and menstrual irregularity. Imaging shows an enlarged anterior pituitary. A prolactin-secreting lesion is suspected. Histologically, this tumour is most likely a:
Galactorrhoea with oligomenorrhoea and a pituitary mass indicates a prolactinoma, a benign adenoma of lactotroph cells. Hamartomas and choristomas are non-neoplastic tissue malformations.
A benign epithelial tumour may form gland-like acini (e.g., in renal tubules) or grow as solid sheets derived from a glandular organ such as the adrenal cortex. Both patterns are classified as:
Adenoma names any benign epithelial neoplasm that forms glands or arises from glandular tissue, even without acini. Carcinoma is malignant; fibroma is mesenchymal; papilloma has finger-like projections.
Which factor lowers a woman's lifetime risk of breast cancer?
Early and multiple full-term pregnancies (and breastfeeding) reduce lifetime oestrogen exposure and lower risk. Early menarche, late menopause and ageing all raise it.
Enlargement of the left supraclavicular (Virchow) node, known as Troisier sign, classically indicates metastasis from a primary cancer of the:
Virchow's node receives lymph via the thoracic duct from abdominal organs, so its enlargement classically signals gastric (or other abdominal) cancer. Glioblastoma rarely metastasizes, and uveal melanoma and osteosarcoma spread mainly by the bloodstream to liver and lungs.
Which pairing of tumour and causative agent is INCORRECT?
Hepatitis A causes only acute infection. Hepatocellular carcinoma is linked to chronic hepatitis B and C, aflatoxin and cirrhosis.
Teratomas arise from which type of cell?
Totipotent germ cells, usually in the gonads, can differentiate into any tissue, explaining the mixture of ectodermal, mesodermal and endodermal tissues in teratomas.
A tumor composed of highly pleomorphic cells with no resemblance to any normal tissue is described as:
Anaplasia means lack of differentiation. Benign tumors are well differentiated, and many malignant tumors still show some differentiation.
Renal tubular epithelium develops from mesoderm. A malignant tumor arising from it is termed a:
Malignant epithelial tumors are carcinomas whatever their germ-layer origin; e.g., renal cell carcinoma arises from mesoderm-derived epithelium. Sarcomas arise from mesenchymal tissue.
Which oncogenic virus has an RNA genome?
HTLV-1 is an RNA retrovirus causing adult T-cell leukemia/lymphoma. EBV, KSHV and HBV are DNA viruses (HBV replicates through an RNA intermediate).
Which HTLV-1 protein activates host growth genes, supports T-cell survival and disrupts cell-cycle checkpoints, driving transformation?
Tax transactivates viral and host genes (e.g., NF-kB targets, IL-2 pathways) and inactivates checkpoint controls. Rex regulates viral RNA export, not proliferation.
A man from south-western Japan has hypercalcaemia, skin lesions and circulating 'flower cells'. Which virus is causally linked?
Adult T-cell leukaemia/lymphoma, with flower-shaped nuclei and hypercalcaemia, is caused by HTLV-1, endemic in Japan and the Caribbean. HTLV-2 lacks a clear disease link.
Which carcinogen is a natural fungal product that must be metabolically activated in the liver before it damages DNA?
Aflatoxin B1 from Aspergillus is an indirect-acting carcinogen activated by hepatic P450 enzymes. The other three are direct-acting alkylating agents.
Osteoblastic (sclerotic) metastases in the lumbar spine of an older man most likely come from:
Prostate cancer spreads preferentially to bone and typically produces bone-forming lesions. Renal cell carcinoma metastases are usually lytic.
Which virus is NOT an established cause of human cancer?
HSV is not recognised as oncogenic. Merkel cell polyomavirus causes Merkel cell carcinoma, EBV several lymphomas and nasopharyngeal carcinoma, HTLV-1 ATLL.
Renal cell carcinoma characteristically invades which route, sometimes extending as a tumour column to the right atrium?
RCC tends to grow into the renal vein and up the IVC in a snake-like column, occasionally reaching the right heart.
During sentinel lymph node biopsy for breast cancer, the first draining node is located by injecting:
Vital blue dye (e.g., isosulfan blue) and/or a radiotracer tracks lymph to the sentinel node. The others are histochemical stains used on tissue sections.