MLT GlobeBasic Pathology: Neoplasia – page 6
120 Basic Pathology MCQs on Neoplasia with answers and explanations.
A lung carcinoma of non-endocrine origin causes Cushing syndrome by releasing ACTH. This phenomenon is best described as:
Some non-endocrine cancers secrete hormones not normally made by their tissue of origin, producing paraneoplastic syndromes such as ectopic ACTH-related Cushing syndrome.
Which cytological feature is typical of anaplastic tumour cells?
Anaplastic cells show pleomorphism, hyperchromatic enlarged nuclei, high N:C ratios, prominent nucleoli, giant cells and atypical mitoses, reflecting loss of differentiation.
Tumour cells within a single neoplasm usually resemble one another because the neoplasm is:
Neoplasms are clonal proliferations descended from a single transformed cell; X-linked marker studies (e.g. G6PD isoforms) demonstrate this monoclonality.
The name given to a tumour (for example, adenoma or osteosarcoma) is based primarily on which component?
All tumours have neoplastic parenchyma and reactive stroma; classification and biological behaviour depend on the parenchymal cells.
Which of the following polyps is inflammatory rather than neoplastic in origin?
Nasal polyps arise from chronic inflammation and oedema of sinonasal mucosa. Adenomatous polyps of the colon are true neoplasms with malignant potential.
A farmer's sun-exposed facial skin shows actinic keratosis on biopsy. This change is best described as:
Actinic keratosis shows disordered growth with atypical keratinocytes in the lower epidermis, a premalignant dysplasia that may progress to squamous cell carcinoma.
A heavy smoker with small cell lung carcinoma and liver metastases develops muscle weakness, raised blood glucose and hypertension. The most likely explanation is:
Small cell carcinoma commonly secretes ACTH, producing Cushing-like features: hyperglycaemia, hypertension and proximal myopathy. Renal artery thrombosis would not raise glucose.
A testicular mass is excised from a 39-year-old man. Which finding proves most convincingly that it is malignant?
Distant metastasis is the only unequivocal criterion of malignancy. Mitoses and nuclear pleomorphism can occur in benign or reactive lesions.
The tumor suppressor gene most frequently mutated across human cancers is:
TP53 mutations occur in about half of all malignancies. APC, BRCA1 and RB1 are important but restricted to particular tumor types.
In adults, which type of tumour is found most often within the brain?
Secondary deposits (e.g. from lung or breast cancer) outnumber primary brain tumours in adults. Primary tumours mostly arise from glial or meningeal cells, rarely from neurones.
Which antigen is a normal tissue differentiation product whose serum level is used to monitor carcinoma of its organ of origin?
PSA is made by normal and malignant prostatic epithelium, so it is a differentiation antigen useful as a tumor marker. MAGE is a cancer-testis antigen; KRAS and E6/E7 are mutant or viral neoantigens.
A tumor arising from the meninges shows frank anaplasia with about 25 mitoses per 10 high-power fields. Under the current WHO CNS classification (CNS5, 2021) it is best termed:
Most meningiomas are CNS WHO grade 1. Brain invasion or 4-19 mitoses/10 HPF defines grade 2; frank anaplasia or at least 20 mitoses/10 HPF (or TERT promoter mutation or homozygous CDKN2A/B deletion) defines grade 3.
Chronic infection with HBV or HCV accounts for approximately what proportion of hepatocellular carcinomas worldwide?
Most hepatocellular carcinomas worldwide (about 70-85%) arise on a background of chronic HBV or HCV infection; alcohol, aflatoxin and metabolic liver disease account for the rest.
Which carcinogen acts directly, without metabolic activation, and belongs to the group of alkylating agents?
Direct-acting carcinogens such as dimethyl sulfate and diepoxybutane need no conversion; they are weak but important, and some alkylating chemotherapy drugs are in this group. The others require metabolic activation.
Years after abdominal surgery, a firm, locally infiltrative fibroblastic mass arises in the scar and recurs after excision but does not metastasise. It is best termed:
Desmoids are infiltrative fibroblastic proliferations that recur locally but do not metastasise. Proud flesh is excess granulation tissue in a healing wound.
Among patients with a newly diagnosed solid tumour, roughly what extra proportion already has occult metastases?
Around 30% present with clinically evident metastases and roughly a further 20% have hidden metastases at diagnosis.
About what proportion of patients with a newly diagnosed solid tumour (excluding non-melanoma skin cancer) have clinically evident metastases?
Roughly 30% present with overt metastases, which is why staging investigations are part of the initial work-up.
A benign tumour of a single germ-layer origin containing both epithelial and myxoid or cartilage-like stromal elements is:
Mixed tumours arise from one germ layer but differentiate into more than one cell type. Teratomas derive from multiple germ layers.
Which testicular germ cell tumour behaves benignly when it arises in prepubertal boys?
Prepubertal teratomas are benign, whereas postpubertal testicular germ cell tumours, including teratomas, are regarded as malignant.
A patient develops acanthosis nigricans with no endocrine cause. If this is paraneoplastic, the most likely underlying cancer is in the:
Paraneoplastic acanthosis nigricans is most often associated with gastric adenocarcinoma. Pigmented velvety skin in the flexures may precede diagnosis of the cancer.