MCQ Nodules Interlobular Septa

L1 Question 1:
Which of the following best describes a nodule located on the interlobular septa?

a) A round opacity centered within the secondary pulmonary lobule
b) A nodule along the thin connective tissue walls separating pulmonary lobules
c) A solid nodule located centrally within the lung hilum
d) A cystic lesion with central necrosis
e) A nodule confined to the alveolar spaces

Answer:
b) A nodule along the thin connective tissue walls separating pulmonary lobules

Comment:
Nodules on the interlobular septa are small opacities along the thin connective tissue separating secondary pulmonary lobules, often associated with perilymphatic or vascular disease.
“Nodules on the interlobular septa are small opacities seen along the connective tissue walls that separate pulmonary lobules, often due to lymphatic or vascular processes.” Radiopaedia

Incorrect Answers:

  • a) “Centrilobular nodules occur within the lobule rather than the septa, often in conditions like hypersensitivity pneumonitis.” Radiopaedia
  • c) “Hilar nodules are more commonly due to lymphadenopathy, such as in lymphoma, not septal nodules.” Radiology Key
  • d) “Cystic lesions with necrosis are more characteristic of necrotizing infections, not nodules along the septa.” Radiopaedia
  • e) “Alveolar nodules are located within the alveolar spaces and are often linked to pneumonia or alveolar hemorrhage.” Radiology Key

L1 Question 2:
Which of the following conditions is most commonly associated with nodules along the interlobular septa?

a) Sarcoidosis
b) Hypersensitivity pneumonitis
c) Centrilobular emphysema
d) Cryptogenic organizing pneumonia (COP)
e) Pneumocystis pneumonia

Answer:
a) Sarcoidosis

Comment:
Sarcoidosis frequently involves perilymphatic nodules, including those along the interlobular septa, as part of its systemic granulomatous spread.
“Perilymphatic nodules along the interlobular septa are a hallmark of sarcoidosis.” Radiopaedia

Incorrect Answers:

  • b) “Hypersensitivity pneumonitis presents with centrilobular nodules rather than septal nodules.” Radiology Key
  • c) “Centrilobular emphysema is characterized by areas of low attenuation rather than nodular opacities.” Radiopaedia
  • d) “COP typically presents with subpleural consolidations rather than nodular septal involvement.” Radiographics
  • e) “Pneumocystis pneumonia typically presents as diffuse ground-glass opacity, not septal nodules.” Radiopaedia

L1 Question 3:
Which imaging sign describes nodules along the interlobular septa?

a) Halo sign
b) Tree-in-bud pattern
c) Beaded septum sign
d) Crazy paving pattern
e) Atoll sign

Answer:
c) Beaded septum sign

Comment:
The beaded septum sign describes nodules along the interlobular septa, commonly seen in sarcoidosis and lymphangitic carcinomatosis.
“The beaded septum sign refers to nodular thickening along the interlobular septa, often seen in sarcoidosis and lymphangitic carcinomatosis.” Radiopaedia

Incorrect Answers:

  • a) “The halo sign describes ground-glass opacity surrounding a denser nodule, often seen in angioinvasive fungal infections.” Radiopaedia
  • b) “The tree-in-bud pattern indicates endobronchial infection, not septal nodules.” Radiopaedia
  • d) “Crazy paving describes ground-glass opacity with superimposed septal thickening, not isolated septal nodules.” Radiology Key
  • e) “The atoll sign describes a ring of consolidation with central clearing, often seen in COP, not septal nodules.” Radiopaedia

L2 (Advanced Clinical Integration)

L2 Question 6:
A 42-year-old male presents with new-onset complete heart block and dyspnea. Chest CT reveals bilateral nodules along the interlobular septa with no hilar lymphadenopathy. What is the most likely diagnosis?

a) Sarcoidosis
b) Lymphangitic carcinomatosis
c) Hypersensitivity pneumonitis
d) Tuberculosis
e) Rheumatoid nodules

Answer:
a) Sarcoidosis

Comment:
Sarcoidosis commonly involves the interlobular septa and can lead to cardiac conduction abnormalities, including heart block.
“Sarcoidosis is a systemic granulomatous disorder frequently affecting the perilymphatic regions of the lung and can involve the cardiac conduction system.” Radiopaedia

Incorrect Answers:

  • b) “Lymphangitic carcinomatosis typically involves progressive dyspnea and irregular septal thickening but not heart block.” Radiopaedia
  • c) “Hypersensitivity pneumonitis primarily involves centrilobular nodules, not septal nodules.” Radiology Key
  • d) “Tuberculosis may involve lymphadenopathy but typically presents with cavitation, not heart block.” Radiopaedia
  • e) “Rheumatoid nodules rarely cause cardiac involvement and more commonly affect the pleura.” Radiographics

 

L2 Question 7:

A 60-year-old patient with a history of renal cell carcinoma presents with progressive dyspnea and interlobular septal nodules on chest CT. PET-CT reveals intense metabolic activity (SUV >7.0). What is the most likely diagnosis?

a) Sarcoidosis
b) Lymphangitic carcinomatosis
c) Tuberculosis
d) Pulmonary edema
e) Silicosis

Answer:
b) Lymphangitic carcinomatosis

Comment:
Lymphangitic carcinomatosis frequently presents with septal thickening and high metabolic activity on PET-CT, particularly in patients with a history of malignancy.
“Lymphangitic carcinomatosis presents with irregular septal thickening, nodular septal involvement, and metabolic activity on PET, especially in metastatic disease.” Radiopaedia

Incorrect Answers:

  • a) “Sarcoidosis involves perilymphatic nodules but rarely demonstrates such intense metabolic activity in the absence of other systemic findings.” Radiopaedia
  • c) “Tuberculosis can present with nodular thickening but often includes cavitation and upper lobe predominance.” Radiology Key
  • d) “Pulmonary edema typically presents with smooth septal thickening and lacks significant PET uptake.” Radiopaedia
  • e) “Silicosis presents with calcified nodules and does not usually demonstrate high metabolic activity.” Radiopaedia

L2 Question 8:

A 50-year-old male presents with acute dyspnea after chemotherapy. CT shows nodular thickening along the interlobular septa with a right pleural effusion. Which condition is the most likely cause?

a) Lymphangitic carcinomatosis
b) Pulmonary edema
c) Sarcoidosis
d) Rheumatoid nodules
e) Tuberculosis

Answer:
b) Pulmonary edema

Comment:
Pulmonary edema frequently presents with smooth septal thickening, interlobular septal nodules, and pleural effusion, especially in cardiogenic cases or fluid overload situations.
“Pulmonary edema often results in smooth septal thickening with pleural effusion and is commonly seen with heart failure or fluid overload.” Radiopaedia

Incorrect Answers:

  • a) “Lymphangitic carcinomatosis typically presents with irregular nodular septal thickening and no pleural effusion.” Radiopaedia
  • c) “Sarcoidosis presents with septal nodules but typically without pleural effusion.” Radiopaedia
  • d) “Rheumatoid nodules are usually pleural-based, not septal, and do not commonly present with effusion.” Radiopaedia
  • e) “Tuberculosis more commonly involves cavitation and upper lobe nodules rather than septal thickening.” Radiology Key

L2 Question 9:

A patient presents with fever, cough, and interlobular septal nodules on CT. Which infectious cause is most commonly associated with this pattern?

a) Tuberculosis
b) Pneumocystis jiroveci pneumonia (PJP)
c) Histoplasmosis
d) Cryptococcus
e) Influenza pneumonia

Answer:
a) Tuberculosis

Comment:
Tuberculosis commonly spreads along the lymphatic channels and presents with nodular thickening along the interlobular septa, particularly in miliary TB or primary progressive disease.
“Tuberculosis often involves the perilymphatic regions, including the interlobular septa, in both primary and miliary TB presentations.” Radiopaedia

Incorrect Answers:

  • b) “PJP often presents with bilateral ground-glass opacities rather than nodular septal thickening.” Radiology Key
  • c) “Histoplasmosis typically involves calcified granulomas rather than active septal nodules.” Radiopaedia
  • d) “Cryptococcus more commonly presents with solitary or miliary nodules, not septal nodular thickening.” Radiopaedia
  • e) “Influenza pneumonia rarely involves nodular septal thickening, instead showing ground-glass opacity and consolidation.” Radiopaedia

L2 Question 10:

A 38-year-old male presents with persistent cough and night sweats. CT reveals small nodules along the interlobular septa and bilateral hilar lymphadenopathy. Which test would best establish the diagnosis?

a) Bronchoscopy with biopsy
b) PET-CT
c) HRCT with expiratory imaging
d) Sputum culture for AFB
e) Serum ACE levels

Answer:
a) Bronchoscopy with biopsy

Comment:
Bronchoscopy with biopsy provides histological confirmation in cases like sarcoidosis, where lymphatic spread along the septa is suspected.
“Bronchoscopy with biopsy is the diagnostic standard for confirming granulomatous diseases such as sarcoidosis with septal involvement.” Radiopaedia

Incorrect Answers:

  • b) “PET-CT may identify metabolic activity but does not provide histological confirmation.” Radiopaedia
  • c) “HRCT with expiratory imaging is more useful in small airway disease than in septal nodules.” Radiology Key
  • d) “Sputum cultures may be helpful in tuberculosis but not in non-infectious nodular septal disease.” Radiopaedia
  • e) “Serum ACE levels can support a diagnosis of sarcoidosis but are not confirmatory without histology.” Radiology Key