MBBS Pathology 2 — Questions and Answers
Question 1: Which genetic mutation is associated with chronic myeloid leukemia (CML)?
- BCL-2 translocation t(14;18)
- BCR-ABL fusion t(9;22) Philadelphia chromosome (Correct answer)
- MYC translocation t(8;14)
- PML-RARA fusion t(15;17)
Correct answer: BCR-ABL fusion t(9;22) Philadelphia chromosome
CML is characterized by the Philadelphia chromosome, resulting from t(9;22) translocation creating BCR-ABL fusion, a constitutively active tyrosine kinase.
Question 2: What is the most common cause of community-acquired pneumonia (CAP) in adults?
- Mycoplasma pneumoniae
- Haemophilus influenzae
- Streptococcus pneumoniae (Correct answer)
- Legionella pneumophila
Correct answer: Streptococcus pneumoniae
Streptococcus pneumoniae is the most common cause of bacterial community-acquired pneumonia in adults across all age groups.
Question 3: Which histological finding is characteristic of Crohn's disease but NOT ulcerative colitis?
- Crypt abscesses
- Goblet cell depletion
- Non-caseating granulomas (Correct answer)
- Mucosal inflammation
Correct answer: Non-caseating granulomas
Non-caseating granulomas are found in approximately 50% of Crohn's disease cases and represent a hallmark distinguishing it from ulcerative colitis.
Question 4: Mallory bodies (Mallory-Denk bodies) in hepatocytes are associated with which condition?
- Viral hepatitis B
- Alcoholic liver disease (Correct answer)
- Primary biliary cirrhosis
- Hemochromatosis
Correct answer: Alcoholic liver disease
Mallory bodies are aggregates of cytokeratin intermediate filaments found in hepatocytes damaged by alcohol, representing a hallmark of alcoholic hepatitis.
Question 5: Which cell type is the primary effector in granuloma formation?
- Neutrophils
- Epithelioid macrophages and giant cells (Correct answer)
- NK cells
- Plasma cells
Correct answer: Epithelioid macrophages and giant cells
Granulomas consist primarily of activated epithelioid macrophages and multinucleated giant cells, organized to wall off persistent antigens.
Question 6: Psammoma bodies are calcified concentric rings found in which tumor?
- Glioblastoma multiforme
- Papillary thyroid carcinoma (Correct answer)
- Small cell lung cancer
- Hepatocellular carcinoma
Correct answer: Papillary thyroid carcinoma
Psammoma bodies are found in papillary thyroid carcinoma, papillary serous ovarian carcinoma, and meningiomas.
MBBS Pathology 2
Which genetic mutation is associated with chronic myeloid leukemia (CML)?