MCQ Cavitating Nodules

L1 Question 1: What is a cavitating nodule in the lungs?

  • a) A solid nodule with calcification
  • b) A nodule containing a gas-filled space or necrosis
  • c) A ground-glass opacity with central clearing
  • d) A solid mass with no central lucency

Answer: b) A nodule containing a gas-filled space or necrosis

Comments

Cavitating nodules are pulmonary nodules containing gas-filled spaces or necrosis, commonly associated with infections, neoplasms, or inflammatory conditions. “Cavitating nodules refer to pulmonary nodules containing necrotic or gas-filled spaces visible on imaging.” Radiopaedia

Incorrect Answers

  • a) Solid nodules with calcification typically represent granulomas, not cavitating nodules. Radiographics
  • c) Ground-glass opacities with central clearing are more typical of organizing pneumonia. Radiopaedia
  • d) Solid masses without central lucency do not meet the definition of cavitating nodules. Radiopaedia

L1 Question 2: Which of the following infections is most likely to cause cavitating nodules?

  • a) Tuberculosis
  • b) Pneumocystis jirovecii pneumonia (PJP)
  • c) Staphylococcus aureus pneumonia
  • d) Viral pneumonia

Answer: a) Tuberculosis and c) Staphylococcus aureus pneumonia

Comments

Tuberculosis and Staphylococcus aureus pneumonia are both well-documented causes of cavitating lung nodules. Reactivation tuberculosis commonly affects the upper lobes, while Staphylococcus aureus pneumonia may cause necrotizing pneumonia leading to cavitation. “Reactivation tuberculosis commonly presents with cavitary lesions, particularly in the upper lobes.” Radiopaedia “Staphylococcus aureus pneumonia can result in necrotizing cavitary lung nodules, especially in severe cases.” Radiographics

Incorrect Answers

  • b) Pneumocystis jirovecii pneumonia (PJP) more commonly presents with diffuse ground-glass opacities rather than cavitation. Radiopaedia
  • d) Viral pneumonia typically results in diffuse ground-glass opacities and rarely causes cavitation. Radiographics

L1 Question 3: Which imaging finding is most concerning for malignancy in a cavitating nodule?

  • a) Thin-walled cavity with smooth margins
  • b) Thick-walled cavity (>15 mm) with irregular margins
  • c) Bilateral cavitating nodules
  • d) Cavities with air-fluid levels

Answer: b) Thick-walled cavity (>15 mm) with irregular margins

Comments

Thick-walled cavities with irregular margins are highly suggestive of malignancy, especially squamous cell carcinoma. “Thick-walled cavitating nodules (>15 mm) with irregular margins are often seen in primary lung malignancies such as squamous cell carcinoma.” Radiographics

Incorrect Answers

  • a) Thin-walled cavities are often seen in benign processes like abscesses. Radiopaedia
  • c) Bilateral cavitating nodules suggest septic emboli rather than malignancy. Radiopaedia
  • d) Air-fluid levels can be seen in both infection and malignancy but are not a definitive sign of cancer. Radiopaedia

L1 Question 4: Which of the following wall thickness patterns in cavitating lung nodules would raise the highest concern for malignancy or an aggressive infectious process?

  • a) Thin-walled cyst (<2 mm) with no change over a year
  • b) Thin-walled cyst (<2 mm) increasing to 6 mm over 6 months
  • c) Thick-walled cavity (>15 mm) in an immunocompromised patient with fever and elevated white count
  • d) Thin-walled cavity with smooth margins

Answer: b) Thin-walled cyst (<2 mm) increasing to 6 mm over 6 months and c) Thick-walled cavity (>15 mm) in an immunocompromised patient with fever and elevated white count

Comments

A thin-walled cyst increasing in size over a short period raises suspicion for malignancy. Similarly, a thick-walled cavity in an immunocompromised patient with systemic signs suggests an aggressive infectious process like necrotizing pneumonia. “Thick-walled cavities with irregular margins or enlarging cystic lesions should raise concern for malignancy or aggressive infection.” Radiopaedia

L1 Question 5: Which of the following conditions is least likely to present with cavitating nodules?

  • a) Tuberculosis
  • b) Rheumatoid nodules
  • c) Bronchogenic carcinoma
  • d) Viral pneumonia

Answer: d) Viral pneumonia

Comments

Viral pneumonia typically presents with diffuse ground-glass opacities rather than cavitating nodules. “Viral pneumonia is less likely to cavitate compared to bacterial and fungal infections.” Radiographics

L2 Question 6: A 55-year-old female with a history of rheumatoid arthritis presents with a solitary cavitating nodule in the right lower lobe. She denies smoking and has no infectious symptoms. What is the most likely diagnosis?

  • a) Tuberculosis
  • b) Rheumatoid nodule
  • c) Squamous cell carcinoma
  • d) Pulmonary infarct

Answer: b) Rheumatoid nodule

Comments

Rheumatoid nodules can cavitate and are often seen in patients with long-standing rheumatoid arthritis, particularly those with positive rheumatoid factor. “Rheumatoid nodules may present as cavitating lesions in the lung, often in patients with long-standing rheumatoid arthritis.” Radiographics

L2 Question 7: What imaging sign is highly specific for septic emboli in cavitating nodules?

  • a) Halo sign
  • b) Feeding vessel sign
  • c) Air crescent sign
  • d) Tree-in-bud pattern

Answer: b) Feeding vessel sign

Comments

The feeding vessel sign, where a vessel is seen entering a cavitating nodule, is characteristic of septic emboli. “The feeding vessel sign is a classic feature of septic emboli, representing the vascular origin of the infection.” Radiographics

L2 Question 8: A 45-year-old male with a history of IV drug use presents with multiple bilateral cavitating nodules on CT. What is the most likely diagnosis?

  • a) Septic emboli
  • b) Sarcoidosis
  • c) Tuberculosis
  • d) Lymphangitic carcinomatosis

Answer: a) Septic emboli

Comments

Septic emboli typically present as multiple cavitating nodules with a feeding vessel sign, often seen in IV drug users. “Septic emboli commonly present as multiple cavitating nodules with a peripheral distribution and a feeding vessel sign.” Radiographics

Incorrect Answers

  • b) Sarcoidosis typically presents with non-cavitating perilymphatic nodules. Radiopaedia
  • c) Tuberculosis can cavitate but more commonly presents as a solitary cavitary lesion with upper lobe predilection. Radiopaedia
  • d) Lymphangitic carcinomatosis usually presents with interstitial thickening and nodularity rather than cavitation. Radiopaedia

L2 Question 9: Which of the following infections is least likely to cause cavitating nodules?

  • a) Klebsiella pneumoniae
  • b) Pneumocystis jirovecii pneumonia (PJP)
  • c) Staphylococcus aureus
  • d) Aspergillosis

Answer: b) Pneumocystis jirovecii pneumonia (PJP)

Comments

Pneumocystis jirovecii pneumonia (PJP) typically presents with diffuse ground-glass opacities rather than cavitation. “PJP infection typically presents with diffuse ground-glass opacities and cystic changes rather than cavitary nodules.” Radiopaedia

Incorrect Answers

  • a) Klebsiella pneumoniae can cause cavitation, particularly in necrotizing pneumonia. Radiographics
  • c) Staphylococcus aureus is a well-documented cause of necrotizing pneumonia with cavitation. Radiopaedia
  • d) Aspergillosis can cause cavitation, especially with invasive forms. Radiopaedia

L2 Question 10: A 62-year-old male with a 40-pack-year smoking history undergoes a routine lung cancer screening CT which reveals a new solitary cavitating nodule in the right upper lobe, measuring 12 mm with irregular margins. What is the appropriate lung cancer screening category and follow-up according to the Lung-RADS criteria?

  • a) Lung-RADS 3, follow-up CT in 6 months
  • b) Lung-RADS 4A, follow-up CT in 3 months
  • c) Lung-RADS 2, no follow-up needed
  • d) Lung-RADS 4B, PET-CT and tissue sampling

Answer: d) Lung-RADS 4B, PET-CT and tissue sampling

Comments

A solitary cavitating nodule with irregular margins >8 mm in a high-risk smoker is classified as Lung-RADS 4B due to highly suspicious features for malignancy. PET-CT and tissue sampling are recommended for further evaluation. “Lung-RADS 4B indicates highly suspicious nodules, typically requiring PET-CT and tissue sampling for definitive diagnosis.” American College of Radiology (ACR)

Incorrect Answers

  • a) Lung-RADS 3 applies to nodules 6-8 mm in size with a lower malignancy risk and would not apply to a 12 mm nodule. ACR
  • b) Lung-RADS 4A is for nodules >8 mm with moderate suspicion for malignancy, while 4B is used when features are highly suspicious and warrant tissue sampling. ACR
  • c) Lung-RADS 2 is for clearly benign nodules, such as those with benign calcification patterns or small stable lesions, which does not describe the irregular cavitating nodule seen here. ACR