Lungs
2. Findings and Diagnosis
59-year-old male presents with history of scleroderma, Raynaud’s disease, and ILD
Upper Image
Axial CT shows bibasilar peripheral reticular changes, ground glass, bronchiectasis, and bronchiolectasis with volume and with crowding of the bronchovascular bundles posteriorly. There is subpleural sparing posteriorly. Note air-fluid level in the distended esophagus.Lower Image
The lower image focuses on the traction bronchiectasis caused by the fibrotic processAshley Davidoff MD TheCommonVein.net 110Lu 136598c
Clinical Context
| Feature | Description |
|---|---|
| Age/Sex | 59-year-old male |
| History | Known scleroderma (systemic sclerosis) |
| Symptoms | Progressive shortness of breath |
| Modality | CT chest (lung and soft tissue windows) |
| Focus | Fibrosing interstitial lung disease in autoimmune context |
Radiologic Findings
| Finding | Description |
|---|---|
| Bibasilar bronchiectasis | Dilated bronchi most pronounced in the lower lobes |
| Traction bronchiectasis | Bronchi pulled apart due to fibrotic lung retraction |
| Reticulation | Fine interstitial lines, especially subpleural and basal |
| Volume loss | Mild shrinkage of lower lobes with posterior displacement of fissures |
| Architectural distortion | Abnormal lung anatomy due to chronic fibrosis |
| Air-fluid level in esophagus | Suggests esophageal dysmotility — common in scleroderma |
Explanation of Radiologic Terms
| Term | Definition |
|---|---|
| Bronchiectasis | Irreversible dilation of bronchi due to airway wall damage |
| Traction bronchiectasis | Bronchial dilation caused by fibrotic retraction of surrounding parenchyma |
| Reticulation | Interlacing linear opacities representing fibrosis or thickened interstitium |
| Volume loss | Reduction in lobe size due to fibrotic scarring or chronic collapse |
| Architectural distortion | Displacement of bronchi, vessels, and fissures due to underlying fibrosis |
| Air-fluid level (esophagus) | Indicative of impaired peristalsis and reflux, often seen in scleroderma |
Anatomical Basis for Radiologic Patterns in NSIP
| Imaging Feature | Underlying Explanation |
| Basal predominance | – Gravity-dependent circulation leads to higher perfusion and lymphatic drainage in lower lobes.- Inflammation and fibrosis may be amplified in these regions, especially in CTDs like scleroderma. |
| Subpleural sparing | – The subpleural lung is less vascularized and more resistant to fibrosis.- In NSIP, inflammation tends to spare these terminal acinar regions, in contrast to UIP where damage begins subpleurally. |
| Bronchovascular distribution | – The interstitium surrounding bronchi and vessels is a primary target for inflammation in NSIP.- Fibrosis follows peribronchovascular connective tissue sheaths, leading to traction bronchiectasis in these regions. |
Differential Diagnosis – Fibrosing Interstitial Lung Disease (ILD)
Most Likely Diagnoses (Bibasilar + Autoimmune Context)
| Disease Category | Specific Diagnosis |
|---|---|
| Inflammatory/Immune | NSIP (fibrotic type) – connective tissue disease–related |
| Inflammatory/Immune | UIP pattern secondary to connective tissue disease (less likely here) |
| Infiltrative | Chronic hypersensitivity pneumonitis (bibasilar but often mid-upper zone) |
Other Less Likely Considerations
| Disease Category | Specific Diagnosis |
|---|---|
| Idiopathic | Idiopathic NSIP |
| Neoplasm – Malignant | Lymphangitic carcinomatosis (usually not tractional) |
| Infection | Chronic post-infectious bronchiectasis |
Key Points & Pearls
-
In scleroderma, the most common ILD pattern is fibrotic NSIP, with bibasilar reticulation, volume loss, and traction bronchiectasis.
-
Traction bronchiectasis is a hallmark of fibrosis — bronchi do not just dilate, they are stretched by scarring.
-
The esophageal air-fluid level reflects systemic involvement of smooth muscle and autonomic dysfunction.
-
CT patterns help distinguish NSIP (uniform, basal) from UIP (patchy, honeycombing).
3. Clinical
Table 1. Clinical Definition and Context: Fibrotic NSIP
| Category | Details |
|---|---|
| What is it | Fibrotic NSIP is a chronic interstitial lung disease characterized by uniform fibrosis and inflammation of the alveolar walls, most often seen in connective tissue disease (CTD) such as scleroderma. |
| Caused by | Most commonly associated with autoimmune disorders, particularly systemic sclerosis (scleroderma), polymyositis/dermatomyositis, and mixed CTD. May also be idiopathic. |
| Resulting in | Progressive fibrosis of the interstitium, leading to volume loss, impaired gas exchange, and restrictive lung disease. |
| Structural changes | Reticulation, traction bronchiectasis, subpleural sparing, and loss of normal alveolar architecture. |
| Functional changes | Reduced lung compliance, restrictive pattern on PFTs, and decreased DLCO. May lead to hypoxia and decreased exercise tolerance. |
| Diagnosis | – Clinical: Progressive dyspnea, cough, CTD symptoms (Raynaud’s, GERD, joint stiffness). – Imaging: High-resolution CT shows bibasilar fibrosis, subpleural sparing, and traction bronchiectasis. – Histology (if needed): Homogeneous fibrosis without temporal heterogeneity. – Other: Positive serologies (ANA, Scl-70) may support underlying CTD. |
| Complications | Pulmonary hypertension, chronic respiratory insufficiency, secondary infection, progression to end-stage lung disease. |
| Treatment | Immunosuppressive therapy (e.g., mycophenolate mofetil, cyclophosphamide), antifibrotics (e.g., nintedanib), oxygen therapy, pulmonary rehab, and monitoring for CTD progression. |
Key Points & Pearls
- Fibrotic NSIP is the most common ILD pattern in scleroderma, and generally has a better prognosis than UIP.
- Subpleural sparing and bronchovascular distribution help distinguish it from other fibrotic patterns.
- Early recognition and diagnosis are crucial for timely immunomodulatory therapy.
- Always evaluate for esophageal involvement and systemic features in patients with suspected CTD-associated ILD.
- Multidisciplinary discussion (MDD) is central to accurate diagnosis and management.
4. Historical and Cultural
1. Etymology and Language
| Concept | Explanation |
|---|---|
| Pneumonia | From Greek pneumon (lung) + -ia (condition) — historically referred to any condition involving the lung, not just infection. In modern usage, it is most often associated with infectious inflammation. In NSIP, “pneumonia” refers to non-infectious inflammation of the interstitium. |
| Interstitial | Latin interstitium, meaning “the space between” — refers to the lung’s connective tissue scaffolding |
| Fibrosis | From Latin fibra (fiber) — abnormal accumulation of fibrous tissue in the lung |
| Sclerosis | Greek skleros (hard) — reflects the stiffening associated with systemic sclerosis |
2. Historical and Cultural Associations
| Theme | Connection |
| Fibrosis and Time | Fibrosis is a disease of accumulation and delay — it evolves slowly, often unnoticed |
| Scleroderma in Art | Rarely depicted explicitly in classical art, but tight skin and stiffness echo through symbolic representation of rigidity |
| Lung Disease in Literature | In La Traviata (Verdi), Violetta’s struggle with consumption mirrors themes of invisible, progressive decay — resonant with fibrotic ILDs |
| The Invisible Enemy | Fibrotic NSIP reflects a broader metaphor — of diseases that silently shape and deform structure without immediate destruction |
| History of NSIP | NSIP was first formally described as a distinct histopathologic pattern by Katzenstein and Fiorelli in 1994, emphasizing its more uniform and less destructive features compared to UIP. |
3. Symbolism and Metaphor
| Metaphor | Interpretation |
| “Whispering fibrosis” | Suggests a slow, persistent progression — a silent force altering architecture over years |
| “Locked lungs” | Represents the restrictive defect — lungs can no longer expand freely, as if imprisoned by scar |
| “Subpleural shadows” | The absence of these shadows in NSIP (subpleural sparing) can itself be symbolic — what isn’t there is the clue |
| “The shrinking curtain” | Cicatricial atelectasis visually and metaphorically resembles a curtain being drawn inward |
4. Artistic Parallels and Diagnostic Philosophy
| Domain | Parallel |
| Visual arts | Impressionist works like Monet’s fog series parallel the subtlety of NSIP’s radiologic signs — diffuse, layered, not sharply defined |
| Poetry | Emily Dickinson’s introspective poetry on breath and silence (“I felt a Funeral, in my Brain”) captures the stillness of ILD |
| Philosophy | Heidegger’s concept of Being-toward-death — slowly progressive conditions invite existential awareness |
| Radiologic insight | Diagnosing fibrotic NSIP requires attunement to subtlety — noticing what is less, not just what is more |
Key Points & Pearls
- Fibrotic NSIP is both a medical and metaphorical condition — slow, quiet, and structurally transformative.
- Its absence of dramatic findings (no honeycombing, no airspace filling) challenges radiologists to perceive negative space.
- The restraint of the disease is mirrored in the discipline of its diagnosis.
- The metaphor of a lung gently stiffening over time captures both the pathophysiology and the narrative of subtle loss.
5. MCQs
Page 6 – Multiple Choice Questions (MCQs)
Basic Science
Q1. What is the histopathologic hallmark of fibrotic NSIP?
A. Temporal heterogeneity with fibroblastic foci
B. Homogeneous fibrosis without honeycombing
C. Necrotizing granulomas
D. Intra-alveolar eosinophils with organizing pneumonia
Correct Answer: B
Explanation: Fibrotic NSIP shows homogeneous fibrosis, unlike UIP, which has temporal heterogeneity and honeycombing.
-
A: Describes UIP
-
C: Suggests granulomatous disease (e.g., sarcoidosis)
-
D: Seen in eosinophilic pneumonia or organizing pneumonia
Q2. Why is NSIP considered a misnomer in the context of the word “pneumonia”?
A. It always coexists with infection
B. It is caused by aspiration
C. It refers to non-infectious interstitial inflammation
D. It is only seen in infants
Correct Answer: C
Explanation: Though “pneumonia” traditionally refers to infection, in NSIP it denotes non-infectious inflammation of the interstitium.
Clinical
Q3. Which connective tissue disease most commonly causes fibrotic NSIP?
A. Rheumatoid arthritis
B. Sjögren’s syndrome
C. Systemic sclerosis (scleroderma)
D. Ankylosing spondylitis
Correct Answer: C
Explanation: Scleroderma is the most common CTD associated with fibrotic NSIP.
Q4. What clinical clue outside the lungs strongly supports CTD-associated ILD?
A. Hemoptysis
B. Cervical lymphadenopathy
C. Esophageal dysmotility
D. Cyanosis
Correct Answer: C
Explanation: Esophageal dysmotility, as seen on imaging or clinically, is a classic feature of scleroderma-related ILD.
Radiology
Q5. Which radiologic feature helps distinguish fibrotic NSIP from UIP?
A. Ground-glass opacity
B. Subpleural sparing
C. Honeycombing
D. Centrilobular nodules
Correct Answer: B
Explanation: Subpleural sparing is a hallmark of NSIP, whereas UIP typically shows subpleural fibrosis.
Q6. Which of the following best explains the bibasilar predominance of fibrosis in NSIP?
A. Low vascular supply in upper lobes
B. Lymphatic and perfusion gradients
C. Smoking-related distribution
D. Primary airway colonization
Correct Answer: B
Explanation: Lower lobes have greater perfusion and lymphatic activity, making them more susceptible to inflammation in NSIP.
Q7. What CT pattern supports the diagnosis of fibrotic NSIP rather than cellular NSIP?
A. Extensive ground-glass opacity
B. Bronchovascular sparing
C. Absence of ground-glass opacity with traction bronchiectasis
D. Consolidation with air bronchograms
Correct Answer: C
Explanation: Fibrotic NSIP shows traction bronchiectasis and minimal to absent GGO, unlike cellular NSIP which is GGO-predominant.
6. Memory Image
Page 7 – Memory Image
Title:
“The Gentle Grip”
Visual Concept (Metaphoric Illustration)
Imagine a fine lace curtain, translucent but gently retracting inward, its threads slowly pulling taut. The edges closest to the window frame remain untouched, delicate and spared.
Beyond it, the trees (bronchovascular bundles) bend as the curtain draws in — their trunks tugged by invisible threads.
The air is still. The scene is quiet, restrained.
There’s no storm, no flood — only the soft fibrosis that reshapes without breaking, that stiffens without collapsing completely.
-
The lace curtain = reticulation + subpleural sparing
-
The gentle pull = traction bronchiectasis and volume loss
-
The stillness = chronicity and non-inflammatory nature of fibrotic NSIP
Memory Caption (Learning Aid)
“NSIP is not the storm, but the stillness after — a slow grip that spares the edge, and stiffens the soul of the lung.”
Key Learning Anchors from the Image
-
Subtle fibrosis with subpleural sparing is the essence of fibrotic NSIP.
-
Unlike UIP, NSIP preserves the border, quietly pulling from the inside out.
-
This image encodes pattern, location, and behavior in a single metaphor — useful for visual memory.