Dr. Irungu Sent SEM 2

Question 1

The chemical carcinogen aflatoxin B1 derived from a fungus which contaminates grain foods most commonly induces:

Accepted Answer

Hepatocellular carcinoma — Aflatoxin B1 from Aspergillus growing on poorly stored grains causes liver cancer.

Question 2

Which pair does NOT correctly match tumour with causative agent?

Accepted Answer

Hepatocellular carcinoma — Hepatitis A virus — Hepatocellular carcinoma is caused by HBV and HCV, not Hepatitis A virus. Hep A never causes chronic infection or cancer.

Question 3

Direct-acting carcinogenic agents:

Accepted Answer

Include medications used in anticancer regimens e.g alkylating agents — Direct-acting carcinogens do not require metabolic conversion. Alkylating agents directly damage DNA.

Question 4

Which is FALSE regarding chemical carcinogens?

Accepted Answer

Promoters such as phorbol esters are directly carcinogenic — Promoters are not carcinogenic alone; they promote the growth of already initiated cells. Initiators are directly carcinogenic.

Question 5

Natural ultraviolet radiation:

Accepted Answer

Damages DNA by forming pyrimidine dimers — UV radiation damages DNA by forming pyrimidine dimers, leading to mutations and skin cancer.

Question 6

The following occupational cancers are correctly matched EXCEPT:

Accepted Answer

Radon — Bone cancer — Radon is associated with lung cancer, not bone cancer.

Question 7

Which is NOT true of H. pylori infection?

Accepted Answer

Sequence: chronic inflammation→atrophy→intestinal metaplasia→dysplasia→cancer — Only a small minority of infected persons develop cancer. Most get gastritis or peptic ulcers.

Question 8

Which statement is NOT true of HBV and HCV?

Accepted Answer

HBV carries multiple genomes encoding viral oncoproteins — HBV has a single small genome and does not carry multiple genomes encoding viral oncoproteins.

Question 9

Screening of cancers:

Accepted Answer

Is application of simple tests across healthy population before symptoms develop — Screening involves applying simple tests to a healthy population before symptoms develop to detect cancer early.

Question 10

Early detection of cancers:

Accepted Answer

Is a concept of timely diagnosis including early diagnosis and screening — Early detection encompasses timely diagnosis, including early diagnosis in symptomatic patients and screening in asymptomatic individuals.

Question 11

Which is NOT true regarding global cancer statistics?

Accepted Answer

About 10 million deaths in 2020 attributed to cancer — The incidence of cancer is increasing globally, not in sharp decline.

Question 12

In Kenya:

Accepted Answer

Risk of developing cancer before age 75 is 14.3% among men and 18% among women — In Kenya, cancer is not the leading cause of death; infectious diseases still lead. The stated risks are correct.

Question 13

One of the following is NOT true regarding precursor lesions:

Accepted Answer

Squamous dysplasia of bronchial mucosa in smokers is a risk factor for lung cancer — Removal of precursor lesions DOES prevent cancer development. That is the purpose of screening and early intervention.

Question 14

Villous adenomas of the colon:

Accepted Answer

Are associated with high risk of transformation to colorectal carcinoma — Villous adenomas have the highest malignant potential among colorectal polyps, with a significant risk of transformation.

Question 15

The following are responsible for alveolar damage in ARDS EXCEPT:

Accepted Answer

Platelet-activating factor (PAF) — IL-10 is an anti-inflammatory cytokine that suppresses inflammation, while the others actively damage alveoli in ARDS.

Question 16

Which is NOT a diffuse obstructive pulmonary disease?

Accepted Answer

Relaxation atelectasis — Atelectasis is lung collapse, not an obstructive disease characterized by difficulty exhaling.

Question 17

Which is NOT a typical finding in COPD?

Accepted Answer

Increased FEV1 to FVC ratio — In COPD, the FEV1 to FVC ratio is DECREASED below 0.70, indicating airflow obstruction.

Question 18

Nasopharyngeal carcinoma:

Accepted Answer

Tends to be radiosensitive — Nasopharyngeal carcinoma has a strong link to EBV and is notably radiosensitive, making radiotherapy a primary treatment.

Question 19

Which tumour suppressor gene abnormality is most common in BOTH SCLC and NSCLC?

Accepted Answer

3p deletions — 3p deletions occur in virtually all lung cancers, regardless of histological type, and involve multiple tumour suppressor genes.

Question 20

Fluid cytopathology specimens include the following EXCEPT:

Accepted Answer

Cystic masses — Lump aspirate is obtained by Fine Needle Aspiration (FNA), which is aspiration cytology, not fluid cytopathology.

Question 21

Which are the most frequent sites of venous thrombosis?

Accepted Answer

Veins of lower extremity — Deep vein thrombosis (DVT) most commonly occurs in the deep veins of the lower extremities.

Question 22

In a state of shock there is:

Accepted Answer

Cardiovascular collapse — Shock is defined as the failure of the cardiovascular system to maintain adequate tissue perfusion, leading to cardiovascular collapse.

Question 23

Which disorder most likely associated with EXUDATE rather than transudate?

Accepted Answer

Suppurative inflammation — Suppurative inflammation, characterized by pus formation, results in exudate, which is protein-rich and inflammatory.

Question 24

Heart failure cells in lungs are actually:

Accepted Answer

Macrophages — Heart failure cells are macrophages that have phagocytosed red blood cells that have leaked into the alveoli due to increased pulmonary venous pressure in left heart failure.

Question 25

Hallmark of ACUTE inflammation:

Accepted Answer

Increased vascular permeability of microcirculation — The key hallmark of acute inflammation is increased vascular permeability, allowing plasma proteins and leukocytes to enter tissues.

Question 26

Hallmark of CHRONIC inflammation:

Accepted Answer

Mononuclear cell infiltration — Chronic inflammation is characterized by infiltration of mononuclear cells like lymphocytes, plasma cells, and macrophages.

Question 27

Granulomatous inflammation is characterized by all the following EXCEPT:

Accepted Answer

Fibroblasts and neovascularization — Central caseous necrosis is typical of tuberculosis and some fungal infections, but not all granulomatous inflammation features it.

Question 28

The hallmark of acute inflammation:

Accepted Answer

Vascular stasis — Increased vascular permeability is the defining hallmark of acute inflammation, leading to the cardinal signs.

Question 29

Which of the following is the hallmark of acute inflammation?

Accepted Answer

Neutrophils — Neutrophils are the characteristic cellular hallmark of acute inflammation, acting as the first responders.

Question 30

Which is a reversible change?

Accepted Answer

Swelling of endoplasmic reticulum — Swelling of organelles, such as the endoplasmic reticulum, is an early reversible change in cell injury.

Question 31

Which mediates systemic effects of inflammation, chemotaxis and stimulates adhesion molecules?

Accepted Answer

Interleukin 1 (IL-1) and tumor necrosis factor — IL-1 and TNF are key mediators of systemic inflammatory effects, including fever and induction of adhesion molecules.

Question 32

Which of the following is a 38 year old man's wound — 4cm circumscribed mass with peripheral brightness on x-ray that gradually resolves — best described as?

Accepted Answer

Metaplasia — The description of a mass with peripheral brightness on X-ray that resolves and is attributed to heterotopic bone formation after trauma is consistent with myositis ossificans, a form of metaplasia.

Question 33

Growth factor elaborated by macrophages recruiting macrophages and fibroblasts and inducing ALL steps of angiogenesis:

Accepted Answer

Fibroblast growth factor — Vascular Endothelial Growth Factor (VEGF) is the primary mediator of angiogenesis, inducing all its steps.

Question 34

A 20-year-old with lacerated wound stitched. One week later prominent raised irregular nodular scar develops. Best describes:

Accepted Answer

Keloid formation — A prominent, raised, irregular nodular scar extending beyond wound margins is characteristic of a keloid.

Question 35

Which of the following is NOT a malignant tumour?

Accepted Answer

Leiomyoma — Leiomyoma is a benign smooth muscle tumor. Its malignant counterpart is leiomyosarcoma.

Question 36

Burkitt lymphoma in Kenya — which lymphoproliferative disorder is common in children?

Accepted Answer

Burkitt Lymphoma — Burkitt Lymphoma is the most common childhood cancer in equatorial Africa, strongly associated with EBV and endemic in the malaria belt.

Question 37

Which tumour marker for ovarian cancer?

Accepted Answer

CA 125 — CA 125 is the primary tumor marker used for ovarian cancer detection and monitoring.

Question 38

True of testicular tumours EXCEPT:

Accepted Answer

Seminomas are insensitive to radiotherapy — Seminomas are highly sensitive to radiotherapy, making it an effective treatment modality.

Question 39

Which is a characteristic feature of pituitary adenomas?

Accepted Answer

Cellular monomorphism and lack of reticulin network — Pituitary adenomas are typically characterized by uniform, monomorphic cells and a loss of the normal reticulin network.

Question 40

H. pylori organisms predominantly demonstrated:

Accepted Answer

Within superficial mucus overlying epithelial cells — H. pylori colonizes the superficial mucus layer overlying gastric epithelial cells.

Question 41

Defects in celiac disease include:

Accepted Answer

Lymphatic transport — Celiac disease affects all stages of nutrient absorption, including intraluminal digestion, terminal digestion, and transport via blood and lymphatics.

Question 42

Features of Vibrio cholerae infection include:

Accepted Answer

Release of chloride ions into lumen after opening of CFTR — Cholera toxin causes excessive chloride ion release into the lumen via CFTR, leading to massive fluid loss.

Question 43

NOT a feature of Crohn's disease:

Accepted Answer

Toxic megacolon — Toxic megacolon is a characteristic complication of Ulcerative Colitis, not typically Crohn's disease.

Question 44

Features of C. difficile infection EXCEPT:

Accepted Answer

Hyperplasia of surface epithelium — C. difficile infection leads to damage and sloughing of the epithelium, not hyperplasia.

Question 45

43-year-old with burning substernal pain. Biopsies show columnar epithelium with goblet cells above GEJ. This represents:

Accepted Answer

Metaplasia — The presence of columnar epithelium with goblet cells above the gastroesophageal junction is known as Barrett's esophagus, a form of intestinal metaplasia.

Question 46

Cervical Intraepithelial Neoplasia:

Accepted Answer

Always manifested by cytological atypia and dysplasia — By definition, CIN represents cytological atypia and dysplasia, which are the cellular changes seen in this precancerous condition.

Question 47

Aetiological theories for endometriosis EXCEPT:

Accepted Answer

Neoplastic theory — The neoplastic theory is not a recognized etiological theory for endometriosis. Theories include regurgitation, metaplasia, and dissemination.

Question 48

True of serous endometrial cancer:

Accepted Answer

TP53 mutations in nearly all cases — TP53 mutations are found in nearly all cases of serous endometrial cancer, which is an aggressive, non-estrogen-dependent subtype.

Question 49

Leiomyomata:

Accepted Answer

Are often asymptomatic and multiple — Leiomyomas (fibroids) are often asymptomatic, multiple, and found in women of reproductive age. They are estrogen-dependent and shrink after menopause.

Question 50

Most frequent tumours of the ovary:

Accepted Answer

Immature teratomas — Surface epithelial-stromal cell tumors are the most common type of ovarian neoplasms, accounting for 65-70% of cases.

Dr. Irungu Sent SEM 2

Questions, Answers & Explanations