Resorption atelectasis (2004 old paper)

Correct Answer: D

Rationale: Resorption atelectasis is commonly seen with bronchial neoplasms (D), causing subtotal obstruction and often localized emphysema, though complete obstruction leads to atelectasis. Choice A is true; complete airway obstruction traps oxygen, which is resorbed, collapsing alveoli without impairing blood flow (Page 714). Choice B is false; mediastinum shifts toward the affected lung due to volume loss, not away (opposite of compressive atelectasis). Choice C is incorrect; it's reversible if obstruction clears (e.g., mucus plug removal), except in chronic contraction cases. Choice E (post-operative) is frequent but not the focus. Page 714 highlights neoplasms as a cause, with obstruction leading to resorption, distinguishing D as a frequent clinical scenario over the inaccurate B or C.

Correct Answer: A

Rationale: Bronchiectasis shows airway dilation up to four times normal size (A), a hallmark of permanent damage. Choice B is false; it affects lower lobes (gravity-dependent). Choice C is incorrect; it's usually bilateral. Choice D is wrong; squamous metaplasia occurs. Choice E (variable histology) is true. Page 728 details A's dilation chronic inflammation/necrosis widens bronchi, with fibrosis or abscesses in severe cases, contrasting with B's lobe error or D's metaplasia denial.

Correct Answer: C

Rationale: Hypersensitivity pneumonitis is partly caused by Type III hypersensitivity (C), with immune complexes and Type IV granulomas. Choice A is false; it's distinct from asthma (alveolar focus). Choice B is incorrect; it's from organic dusts (e.g., fungi), not non-organic. Choice D is wrong; it's allergic alveolitis, not bronchiolitis. Choice E (non-caseating granulomas) is true. Page 739 details C's mechanism antigen-antibody complexes trigger inflammation (e.g., farmer's lung), distinguishing it over A's link or B's dust type.

Correct Answer: A

Rationale: Staph aureus pneumonia is common with endocarditis in IV drug users (A), via hematogenous spread. Choice B is false; it causes complications (e.g., empyema). Choice C is incorrect; Klebsiella, not S aureus, targets malnourished/alcoholics. Choice D is wrong; it follows viral infections (e.g., influenza), not mumps. Choice E (nosocomial) is true. Page 748 links A's association S aureus's virulence in IVDU leads to septic emboli, distinguishing it over B's complication denial or C's group error.

Correct Answer: A

Rationale: Pulmonary non-Hodgkin lymphoma must be excluded in HIV pneumonia (A), due to malignancy risk. Choice B is false; common pathogens (e.g., S pneumoniae) also dominate. Choice C is incorrect; M avium occurs late (CD4 <50). Choice D is wrong; TB strikes early. Choice E (none true) is invalid. Page 757 notes A's necessity lymphoma mimics infection radiologically, distinguishing it over B's exclusion or C's timing error.