Classic spectrum of interstitial lung diseases on HRCT

CLINICAL PROFILE

Patient 1

Figure 1 - A 17-year-old female presents with complaints of progressive dyspnea for the last 2 months. She has been on anti-epileptic drug therapy for the last 3 years.

Figure 1.

(a) HRCT thorax, axial section shows thin walled cysts (red arrows) distributed throughout the lung fields in lymphangiomyomatosis. (b) CT brain, axial scan shows the classic subependymal nodules (green arrows). (c) CECT abdomen, coronal scan, arterial phase, shows a right kidney mid-pole fat containing exophytic lesion which enhances inhomogeneously (pink arrows), suggestive of renal angiomyolipoma

Patient 2

Figure 2 - A 35-year-old male presents with breathlessness and pleutic chest pain for 3 months. He has a past history of smoking, quit 1 year back.

Figure 2.

HRCT thorax, axial scan delineates ill-defined cysts within the lung parenchyma bilaterally with nodules (green arrows)

Patient 3

Figure 3 - A 50-year-old female, known case of rheumatoid arthritis presents with dyspnea when climbing stairs and chest pain for last 6 months.

Figure 3.

HRCT thorax, axial section, shows typical subpleurally layered peripheral cysts stacked one over the other, suggestive of “honeycombing” (purple arrows)

Patient 4

Figure 4 - A 55-year-old male, non-smoker presents with sudden onset of dry cough, breathlessness and malaise for 20 days.

Figure 4.

HRCT thorax (a) axial section and (b) coronal reformatted image reveal patchy consolidation in peribronchial areas (green arrows) with reticular peribronchial nodules and bronchial wall thickening

QUESTIONS

Q1. What are the imaging findings on CT and the likely diagnosis of each?

Q2. Delineate the characteristic clinical and HRCT findings of each of these interstitial lung diseases.

ANSWERS

Patient 1

HRCT thorax [Figure 1a] shows characteristic thin-walled cysts (red arrows) distributed throughout the lung fields in a young female with seizures suggests changes of lymphangiomyomatosis. On CT screening of the brain [Figure 1b], the classic well-defined calcified nodules are noted along the supependymal surface of the lateral ventricles (green arrows). CECT abdomen [Figure 1c] shows an incidental mid-pole fat containing exophytic lesion which enhances inhomogeneously (pink arrows), suggestive of renal angiomyolipoma. The patient was thus diagnosed as a case of tuberous sclerosis.

Clinically:[1]

• A female of child bearing age group

• May be associated with tuberous sclerosis.

HRCT features:[1]

• Thin-walled cysts of equal size throughout the lung parenchyma

• Interlobular septal thickening

• May show dilated thoracic duct

• May demonstrate areas of high attenuation due to hemorrhage

• Recurrent pneumothoraces

• Absence of nodules.

Patient 2

HRCT thorax [Figure 2] shows ill-defined cysts within the lung parenchyma bilaterally with nodules (green arrows) in late cystic Langerhans cell histiocytosis.

Clinically:[2]

• Pediatric patient with Langerhans cell histiocytosis

• Young adult male smoker.

HRCT features:[2]

• Early changes: 1-10 mm centrilobular nodules

• Late changes: Bizarre-shaped cysts

• Emphysema

• Ground glass opacities.

Patient 3

HRCT thorax [Figure 3] shows typical subpleurally layered peripheral cysts stacked one over the other, suggestive of “honeycombing” (purple arrows) in a case of usual interstitial pneumonia.

Clinically:[3]

• Associated with a connective tissue disorder or asbestosis.

HRCT features:[3]

• Subpleural basal predominance

• Honeycombing in the absence of nodules of ground glass opacities

• Traction bronchiectasis.

Patient 4

HRCT thorax axial [Figure 4a] and coronal [Figure 4b] sections demonstrate patchy consolidation in peribronchial areas (green arrows) with reticular peribronchial nodules and bronchial wall thickening, suggestive of cryptogenic organizing pneumonia.

Clinically:[4]

• Commonest in 55-60 years of age groups

• Acute onset of dyspnea, malaise, non-productive cough

• No association with smoking.

HRCT features:[4]

• Patchy consolidation distributed subpleurally or in peribronchial regions

• Nodules of various sizes which may coalesce

• Interlobular septal thickening

• Peribronchial thickening

• Ground glass opacities.

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Conflicts of interest

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