Respiratory Pathology 2 | MCQ Quiz | OmpathStudy Kenya

Question 1

A patient presents with transient pulmonary infiltrates, blood eosinophilia, and a completely benign self-limiting clinical course. No cause is identified. This is best described as:

Accepted Answer

Löffler syndrome (simple pulmonary eosinophilia) — Löffler syndrome = simple pulmonary eosinophilia + transient lesions + benign clinical course. It is self-limiting. Acute eosinophilic pneumonia is more severe with rapid onset hypoxia and BAL 25% eosinophils.

Question 2

BAL fluid in acute eosinophilic pneumonia shows what threshold of eosinophils to support the diagnosis?

Accepted Answer

Greater than 25% eosinophils — Acute eosinophilic pneumonia requires BAL eosinophils 25%. It presents with rapid onset fever, dyspnea, and hypoxia, and responds promptly and dramatically to corticosteroids.

Question 3

A patient with idiopathic chronic eosinophilic pneumonia presents with high fever, night sweats, and dyspnea. CXR shows peripheral infiltrates. This diagnosis requires:

Accepted Answer

Exclusion of all other causes of pulmonary eosinophilia — Idiopathic chronic eosinophilic pneumonia is a diagnosis of exclusion. All other causes (asthma, drug allergies, parasites, vasculitis) must be ruled out first. It characteristically affects the peripheral lung fields.

Question 4

Which of the following correctly describes the eosinophil-activating cytokine central to pulmonary eosinophilia?

Accepted Answer

IL-5 drives eosinophil infiltration and activation — Elevated alveolar IL-5 is the key driver of eosinophil activation in pulmonary eosinophilia. IL-5 is produced by TH2 cells and is also the cytokine responsible for eosinophil activation in asthma.

Question 5

Desquamative interstitial pneumonia (DIP) is best characterized by:

Accepted Answer

Diffuse air space accumulation of smoker's macrophages with mild septal thickening — DIP shows diffuse accumulation of smoker's macrophages (dusty-brown pigment) in air spaces throughout the lung, with mild alveolar septal thickening. The macrophage distribution is diffuse, unlike RB-ILD which is bronchiolocentric.

Question 6

Respiratory bronchiolitis-ILD differs from DIP in that the macrophage distribution is:

Accepted Answer

Concentrated around first and second order respiratory bronchioles — RB-ILD shares the same smoker's macrophages as DIP but in a bronchiolocentric distribution — first and second order respiratory bronchioles. DIP has diffuse air space distribution. Both improve with smoking cessation.

Question 7

A patient with rheumatoid arthritis develops progressive bilateral interstitial lung disease. Biopsy shows diffuse uniform interstitial fibrosis without temporal heterogeneity and no honeycombing. The pattern is:

Accepted Answer

NSIP (nonspecific interstitial pneumonia) pattern — NSIP is the most common pattern in collagen vascular disease lung involvement. It lacks the temporal heterogeneity of UIP and typically has no honeycombing or fibroblastic foci. Prognosis is better than IPF.

Question 8

When a UIP pattern is found on lung biopsy, which of the following must be excluded before diagnosing IPF?

Accepted Answer

Collagen vascular diseases and asbestosis among others — UIP pattern can be seen in asbestosis, collagen vascular diseases, drug reactions, and other conditions. These known causes must be excluded before the diagnosis of IPF (idiopathic) can be made.

Question 9

Bleomycin causes pulmonary toxicity through which mechanism?

Accepted Answer

Direct drug toxicity and inflammatory cell influx into alveoli — Bleomycin causes pneumonitis and interstitial fibrosis through direct drug toxicity combined with stimulation of inflammatory cell influx into the alveoli. Amiodarone similarly causes pneumonitis and fibrosis.

Question 10

Acute radiation pneumonitis characteristically occurs at what time interval after therapy?

Accepted Answer

Between 1 and 6 months after therapy — Acute radiation pneumonitis occurs 1–6 months after therapy in up to 20% of patients. The infiltrates precisely correspond to the radiation field. It may progress to chronic radiation pneumonitis with fibrosis.

Question 11

Idiopathic pulmonary hemosiderosis most commonly affects which age group?

Accepted Answer

Children predominantly — Idiopathic pulmonary hemosiderosis predominantly affects children, though it also occurs in adults who have a better prognosis. Historical mean survival was only 2.5 years, now improved with steroids and immunosuppression.

Question 12

The key feature distinguishing idiopathic pulmonary hemosiderosis from Goodpasture syndrome is:

Accepted Answer

Absence of renal disease and anti-GBM antibody in IPH — Both conditions share hemoptysis, anemia, and diffuse pulmonary infiltrates. IPH lacks renal disease and anti-GBM antibody — the two defining features of Goodpasture syndrome.

Question 13

Wegener granulomatosis causes nasal perforation because of:

Accepted Answer

Granulomatous inflammation eroding the nasal septum — The necrotizing granulomatous inflammation of Wegener granulomatosis in the upper respiratory tract can erode and perforate the nasal septum. Nasal perforation is a classic pathognomonic clinical feature.

Question 14

Lung lesions in Wegener granulomatosis are characterized by which combination?

Accepted Answer

Necrotizing vasculitis combined with necrotizing granulomatous inflammation — Wegener granulomatosis lung lesions have two components: necrotizing vasculitis (angiitis) AND parenchymal necrotizing granulomatous inflammation. Both features together are characteristic of WG.

Question 15

Fat embolism syndrome typically develops within what time frame after long bone fracture?

Accepted Answer

Within 24–72 hours after injury — Fat embolism syndrome (petechiae, neurologic symptoms, respiratory failure) typically develops 24–72 hours after massive trauma or long bone fracture. The mechanism involves mechanical obstruction plus toxic fatty acid release causing endothelial damage.

Question 16

Amniotic fluid embolism is a catastrophic obstetric emergency primarily because it causes:

Accepted Answer

Sudden dyspnea, hypotension, hypoxia, and DIC — Amniotic fluid embolism presents with sudden dyspnea, hypoxia, hypotension, and DIC. It carries high maternal mortality. The mechanism involves fetal squamous cells and debris triggering inflammatory response and coagulopathy in pulmonary microvasculature.

Question 17

Air embolism causes cardiovascular collapse primarily by:

Accepted Answer

Blocking right heart outflow with a large air bolus — A large air bolus causes right heart outflow obstruction leading to cardiovascular collapse. The characteristic auscultatory finding is a "mill wheel" murmur. Common causes are iatrogenic (IV lines, surgery, barotrauma).

Question 18

Blastomyces dermatitidis is pathognomonic for which morphologic finding in tissue?

Accepted Answer

Thick-walled yeast with broad-based budding — Blastomyces dermatitidis forms thick-walled yeast with broad-based budding — this is pathognomonic. Blastomycosis causes mixed suppurative and granulomatous inflammation and is most likely to cause symptomatic disease.

Question 19

The most common extrapulmonary site of dissemination in blastomycosis is:

Accepted Answer

Skin — Skin is the most common extrapulmonary site of blastomycosis dissemination. Contrast with coccidioidomycosis where meningeal involvement is the most serious complication, and histoplasmosis where liver, spleen, and adrenals are affected.

Question 20

In coccidioidomycosis, the most serious complication of dissemination involves:

Accepted Answer

Meningeal involvement — Meningeal involvement is the most serious and life-threatening complication of disseminated coccidioidomycosis. It causes chronic meningitis that is difficult to treat. Dissemination is rare but more likely in immunocompromised patients.

Question 21

Invasive aspergillosis in a neutropenic patient is angioinvasive. The characteristic CT finding in early disease is:

Accepted Answer

Halo sign — ground-glass opacity surrounding a nodule — The "halo sign" on CT (ground-glass opacity surrounding a pulmonary nodule) is characteristic of early invasive aspergillosis. The "air-crescent sign" appears later. Aspergillus shows septate hyphae branching at 45 degrees.

Question 22

Which antifungal is first-line treatment for invasive aspergillosis?

Accepted Answer

Voriconazole — Voriconazole is the first-line treatment for invasive aspergillosis. Diagnosis is supported by galactomannan antigen and beta-D-glucan in serum or BAL. Aspergillus shows septate hyphae branching at 45-degree angles.

Question 23

Which immune defect primarily predisposes to infections with encapsulated bacteria like S. pneumoniae and H. influenzae in the lung?

Accepted Answer

Humoral (antibody) deficiency — Humoral immunodeficiency (antibody/B cell deficiency) primarily predisposes to infections with encapsulated organisms (S. pneumoniae, H. influenzae) that require opsonization by antibody for effective clearance.

Question 24

A transplant recipient develops interstitial pneumonitis. Biopsy shows enlarged cells with large basophilic intranuclear inclusions surrounded by a clear halo. Treatment is:

Accepted Answer

Ganciclovir — CMV pneumonia shows "owl-eye" intranuclear inclusions (large, basophilic, with clear halo) plus cytoplasmic inclusions in enlarged cells. It is the most common viral pneumonia in immunocompromised/transplant patients. Treatment is ganciclovir.

Question 25

A typical carcinoid tumor of the lung differs from atypical carcinoid by:

Accepted Answer

Typical carcinoid has fewer than 2 mitoses per 10 HPF and no necrosis — Typical carcinoid: <2 mitoses/10 HPF, no necrosis, better prognosis ( 90% 5-year survival). Atypical carcinoid: 2–10 mitoses/10 HPF, may have necrosis, worse prognosis (50–70% 5-year survival).

Question 26

Carcinoid syndrome from a pulmonary carcinoid can occur without liver metastases because:

Accepted Answer

Lung carcinoids secrete histamine rather than serotonin systemically — Pulmonary carcinoids drain into pulmonary veins directly into systemic circulation, bypassing the liver. This means serotonin is not metabolized by the liver before reaching systemic circulation, enabling carcinoid syndrome without liver metastases.

Question 27

Malignant mesothelioma begins morphologically as:

Accepted Answer

Small pleural nodules progressing to rind-like lung encasement — Mesothelioma begins as small nodules on the pleural surface, then progresses to sheets of tumor that encircle and encase the lung in a "rind-like" fashion. It presents with chest pain and recurrent hemorrhagic pleural effusion.

Question 28

Which histologic subtype of mesothelioma has the worst prognosis?

Accepted Answer

Sarcomatoid type with spindle cell pattern — Sarcomatoid mesothelioma has the worst prognosis among the three types. Epithelioid (most common) has the best prognosis. Biphasic/mixed is intermediate. Overall median survival is 12–18 months regardless of type.

Question 29

FEV1 is normal but FVC is significantly reduced. The FEV1/FVC ratio is near normal. This spirometry pattern indicates:

Accepted Answer

Restrictive lung disease from reduced compliance — Restrictive lung disease reduces FVC (reduced lung expansion) while FEV1 is proportionately reduced, keeping the FEV1/FVC ratio near normal. This contrasts with obstruction where FEV1 falls disproportionately, lowering the ratio.

Question 30

Secondary eosinophilia in the lung is most commonly associated with which of the following conditions?

Accepted Answer

Asthma, drug allergies, and certain vasculitides — Secondary pulmonary eosinophilia is associated with asthma, drug allergies, and certain vasculitides. It is distinguished from primary/idiopathic causes by having an identifiable underlying condition driving the eosinophilic response.

Respiratory Pathology 2 | MCQ Quiz | OmpathStudy Kenya

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