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New Fleischner IPF classification: what happened to NSIP?
Have been using the new Fleischner system, but am very confused about something: what happened to NSIP? The term isnt even mentioned in the guidelines.
Is that term no longer used? It seems like I am obligated to classify something as typical UIP, probable UIP, indeterminate for UIP, or non UIP.
I used to call many cases with peripheral ground glass opacities and reticulations, without honeycombing as NSIP (either cellular, or if a bit of honeycombing, fibrotic). I was taught that NSIP was a spectrum and fibrotic NSIP overlapped with UIP.
What am I supposed to call cases that I used to call NSIP? Are they all now probable UIP?
Thanks!
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14 Replies
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Quote from radioloqist
Have been using the new Fleischner system, but am very confused about something: what happened to NSIP? The term isnt even mentioned in the guidelines.
Is that term no longer used? It seems like I am obligated to classify something as typical UIP, probable UIP, indeterminate for UIP, or non UIP.
I used to call many cases with peripheral ground glass opacities and reticulations, without honeycombing as NSIP (either cellular, or if a bit of honeycombing, fibrotic). I was taught that NSIP was a spectrum and fibrotic NSIP overlapped with UIP.
What am I supposed to call cases that I used to call NSIP? Are they all now probable UIP?
Thanks!
I wouldn’t call myself a chest radiologist (and certainly am not a member of the Fleischner Society) but, since no one else in my group will take them on, I’m the guy that reads HRCT in my practice. Which is to say, I’m no expert on this but think I know the answer to your question. If what follows is incorrect, I’d happily be corrected.
The four categories you list aren’t quite right. They are:
[ol][*]UIP[*]Probable UIP[*]Indeterminate for UIP[*][u][b]Alternative Diagnosis[/b][/u] (not “non-UIP”) [/ol]
#4 is where you’ll find NSIP, hypersensitivity pneumonitis, COP, etc.
Here’s a link to ATS guidelines: [link=https://www.thoracic.org/statements/resources/interstitial-lung-disease/diagnosis-IPF-full-length.pdf]https://www.thoracic.org/statements/resources/interstitial-lung-disease/diagnosis-IPF-full-length.pdf[/link] (NSIP is noted on page e50 in the section “Alternative Diagnosis”)
And I’m not arguing with your characterization of NSIP but one criteria you didn’t mention is subpleural sparing. If I can’t see subpleural sparing, I’m not calling NSIP (kind of like if there’s no honeycombing, I’m not calling UIP).-
Thanks! What youve written makes sense.
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Can UIP not be reliably diagnosed prior to honeycombed stage?
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yes and no. age and clinical context is very importnat.
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yes and no. age and clinical context is very importnat.
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biopsy.
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A lot of the older guys in my group just call all these chronic interstitial lung disease pulmonary fibrosis or fibrotic changes.
Ive always been confused by this. I usually try and differentiate it between uip, nsip, hp, rb, cop, ep, etc.
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Quote from Dr. Joseph Mama
Quote from radioloqist
Have been using the new Fleischner system, but am very confused about something: what happened to NSIP? The term isnt even mentioned in the guidelines.
Is that term no longer used? It seems like I am obligated to classify something as typical UIP, probable UIP, indeterminate for UIP, or non UIP.
I used to call many cases with peripheral ground glass opacities and reticulations, without honeycombing as NSIP (either cellular, or if a bit of honeycombing, fibrotic). I was taught that NSIP was a spectrum and fibrotic NSIP overlapped with UIP.
What am I supposed to call cases that I used to call NSIP? Are they all now probable UIP?
Thanks!
I wouldn’t call myself a chest radiologist (and certainly am not a member of the Fleischner Society) but, since no one else in my group will take them on, I’m the guy that reads HRCT in my practice. Which is to say, I’m no expert on this but think I know the answer to your question. If what follows is incorrect, I’d happily be corrected.
The four categories you list aren’t quite right. They are:
[ol][*]UIP[*]Probable UIP[*]Indeterminate for UIP[*][u][b]Alternative Diagnosis[/b][/u] (not “non-UIP”) [/ol]
#4 is where you’ll find NSIP, hypersensitivity pneumonitis, COP, etc.Here’s a link to ATS guidelines: [link=https://www.thoracic.org/statements/resources/interstitial-lung-disease/diagnosis-IPF-full-length.pdf]https://www.thoracic.org/statements/resources/interstitial-lung-disease/diagnosis-IPF-full-length.pdf[/link] (NSIP is noted on page e50 in the section “Alternative Diagnosis”)
And I’m not arguing with your characterization of NSIP but one criteria you didn’t mention is subpleural sparing. If I can’t see subpleural sparing, I’m not calling NSIP (kind of like if there’s no honeycombing, I’m not calling UIP).
You can def have NSIP without subpleural sparing. I’ve read analyses where only like 50 % of confirmed cases have subpleural sparing.
[link]https://pubmed.ncbi.nlm.nih.gov/31929532/[/link]-
To quote a famous chest radiologist: ‘Ah, they all look the same anyway.’
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If available, knowing how long they have had it and what underlying conditions they have is helpful to distinguish as well.
UIP pattern is same death trajectory as lung cancer and most cases are idiopathic, some are due to asbestosis.
NSIP has a strong correlation with collagen vascular diseases – the classic patulous esophagus of scleroderma, for example.
Otherwise, that’s why they made the new “probable” and “indeterminate” categories – they are hard to tell sometimes. Some people also have “nonspecific fibrosis of unknown significance/age-related” and aspiration-related fibrosis too.
Outside of an academic center (others please chime in), it seems like most clinicians are happy with fibrosis or not – aka picking out the hallmarks of fibrosis – intralobular septal thickening (“reticulation”), architectural distortion, bronchiectasis, and volume loss.
If you want to classify them, then 1. history/other conditions (including prior imaging) 2. lobe/zone predominance 3. special features – subpleural sparing, honeycombing, ground glass, etc.
Those steps usually suit me pretty well and honestly I’ve never known if anyone even cares when I say it’s likely UIP or likely NSIP or “recommend inspiration/expiration thin cut CT to evaluate for HSP”
I’m not sure this post even matters or why I typed it. lol-
I’ve been told the insurance approval for therapy is contingent on how it’s read, IE a probable UIP can get anti-fibrotics while an indeterminate will not.
Also since NSIP and UIP are treated differently I don’t think saying “non-specific ILD or fibrotic change xyz ” is really helping anyone.-
I hear you, but theres considerable overlap between most of the things named in this post, stable chronic post inflam/infect fibrosis, aspiration, etc and without priors, specific language is often dubious.
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and that too
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you weren’t taught quite right, if there is honeycombing its still very likely UIP unless you have particularly unusual GGO, young patient, collagen vascular disease in which case start to think of NSIP
