0:01

More central lobular nodularity here,

0:03

central Lior nodules.

0:04

So how do we know it's central lobular?

0:07

Well, again, subpleural sparing.

0:09

These are a little more subtle, but they're clearly there.

0:13

But subpleural sparing

0:14

and again, they have an order to them,

0:16

these central lobular nodules.

0:18

And so when you see this degree of central laba

0:20

and nodularity, you wanna first obviously exclude

0:24

the patient having an acute event

0:26

like aspiration or infection.

0:27

But most commonly I'll see this in the

0:29

subacute or chronic setting.

0:30

So if the patient is coming in chronically,

0:33

then really your differential diagnosis is dichotomous.

0:36

So usually in this disease setting we're thinking

0:38

respiratory bronchiolitis from smoking

0:40

or non fibrotic hypersensitivity pneumonitis.

0:44

And so really the diagnosis will be based on clinical

0:46

workup, but that's also quite helpful to the clinician.

0:49

'cause the first thing that they can exclude is a smoking

0:52

related respiratory bronchiolitis.

0:54

If the patient's a 30 pack per year smoking history,

0:57

so significant smoking history, um, then you're thinking

1:00

of respiratory bronchiolitis very high in your

1:01

differential diagnosis.

1:03

If they're a non-smoker, well now you move forward

1:05

and you start to do a detailed history and physical.

1:07

For hypersensitivity pneumonitis, we know

1:10

that smoking is at least somewhat protective

1:13

for hypersensitivity.

1:14

Pneumonitis. Not saying anyone should smoke smoking is bad

1:17

for you, but just from a diagnostic standpoint,

1:20

if you know someone smoking with this central Li Nodularity

1:24

RB goes very high on the DDX

1:25

and HP goes further down on the DDX in terms

1:29

of what's going on.