A 45-year-old pulmonologist is conducting a teaching rounds session for internal medicine residents on the interpretation of high-resolution computed tomography (HRCT) of the chest in interstitial and cystic lung diseases. She presents several classic radiological descriptions and asks the residents to identify the corresponding underlying pathology. Match the following HRCT findings with the most appropriate diagnosis.
- Subpleural reticular opacities, traction bronchiectasis, and honeycombing with a lower lobe predominanceUsual interstitial pneumonia (UIP)
- Irregularly shaped cysts and small centrilobular nodules with a mid-to-upper lung zone predominance and relative sparing of the costophrenic anglesPulmonary Langerhans cell histiocytosis (PLCH)
- Diffuse, round, thin-walled cysts distributed uniformly throughout all lung zones, including the costophrenic angles, with normal intervening parenchymaLymphangioleiomyomatosis (LAM)
- Patchy, migratory areas of consolidation and ground-glass opacities with a perilobular distribution forming a 'reverse halo sign'Cryptogenic organizing pneumonia (COP)
Answer
The correct matches are: Subpleural reticulation/honeycombing to UIP; Irregular cysts/nodules sparing bases to PLCH; Diffuse uniform cysts to LAM; and Patchy consolidation with reverse halo sign to COP.
Each matching pair represents a highly specific pathognomonic HRCT pattern for the associated lung disease. Recognizing the combination of morphological features (e.g., cysts vs. honeycombing) and their distinct craniocaudal distribution is fundamental to establishing a precise radiologic diagnosis.
Step-by-Step Solution
Key Concept
Identifying specific morphological patterns and their craniocaudal distribution on high-resolution computed tomography (HRCT) is essential for diagnosing different interstitial and cystic lung diseases.