Weissleder -- Chest DDx
Terms
undefined, object
copy deck
- What is your approach to reading chest x-rays?
-
Out to in:
1) Humeri -- clavicles -- scapulae -- ribs -- spine
2) Pleural margins (look for PTX, nodularity, thickening, mass, or small effusion)
3) Airways
4) Mediastinum - What areas of the mediastinum do you have to look at?
-
1) Paratracheal stripe
2) AP window
3) Azygoesophageal recess
4) Paraspinal lines
5) Junction lines - What specific structure in the airways must you look at?
- Posterior wall of bronchus intermedius
- What is the next thing you look at?
- Hilar shadows
- Then?
- Pulmonary parenchyma
- What about pulm parenchyma?
-
1) Lung volumes
2) Difference in density between left and right lung
3) Focal or diffuse lung abnormalities - What is approach to reading an ICU film?
-
1) Look at position of lines and tubes
2) Look for pneumothorax or pneumomediastinum
3) Look for focal parenchymal opacities
4) Look for diffuse parenchymal opacities - What is DDx for focal parenchymal opacities?
-
1) Atelectasis
2) Pneumonia
3) Aspiration
4) Contusion
5) Hemorrhage - What is DDx for diffuse opacities in ICU patient?
-
1) Edema
2) Pneumonia
3) ARDS
4) Hemorrhage - When encountering an apparently normal CXR, what is the first thing to look at?
- Bones
- For what?
-
1) Retrocardiac disease
2) Hidden nodules
3) Bronchiectasis
4) Subtle interstitial disease
5) Overall differences in lung density
6) Evidence of PE - What is the second area to look at?
- Mediastinum
- What next?
- Airway
- What is the next area to look at?
- Lungs
- What are signs of right upper lobe collapse?
-
Elevation of minor fissure
Rightward shift of trachea
Elevation of right hilum - What does RUL collapse look like when complete?
- Thickening of right paratracheal stripe
- What are causes of recurrent right middle lobe atelectasis?
- Bronchus surrounded by enlarged lymph nodes
- What is appearance of RLL collapse?
-
Triangular opacity in right retrocardiac region, with obliteration of diaphragm
Opacity over the spine - LUL collapse?
- Difficult to see: Just see hazy density, which can easily be confused with loculated pleural effusion
- What is a sign seen in LUL collapse?
- Luftsichel
- What is luftsichel?
- On PA view, you see an area of lucency surrounded by increased density, which represents the superior segment of the left lower lobe rising up higher now that the left upper lobe is collapsed.
- What does the lateral view look like in LUL collapse?
- The left lower lobe is anterior; thus when it collapses, the minor fissure gets pulled anteriorly with it.
- What is appearance of LLL collapse?
-
Left retrocardiac opacity
On lat view, posterior displacement of the major fissue - What causes lung consolidation?
- Confluence of acinar shadows
- What specifically?
- Fluid, inflammatory exudate, or tissue in acini
- What types of fluid?
-
Water
Blood
Proteinaceous fluid - What causes water in acini?
- Pulmonary edema
- What causes blood in acini?
- Trauma is most common cause
- What are other causes?
-
Bleeding disorder or anticoag
Pulmonary infarct
Vasculitis, including Goodpastures and Henoch-Schonlein - What causes proteinaceous fluid?
- Alveolar proteinosis
- What are general causes of inflammatory exudate in acini?
- Infection and non-infectious inflammation
- What are noninfectious causes?
-
Allergic hypersensitivity pneumonitis
Chronic eosinophilic pneumonia
BOOP
Loeffler's syndrome
ABPA
Aspiration of lipid material
Sarcoidosis - What causes soft tissue in acini?
- Tumor
- Which tumors?
-
Bronchioloalveolar CA
Lymphoma - What is first step in evaluating solitary pulm nodule?
- Assess age and smoking status
- What is the age cutoff?
- 30
- What if patient is under 30 and non-smoker?
- Stop or follow up imaging
- What is the first question to ask if patient is a smoker or is over 30?
- Are there any prior films
- What is the question to ask on the prior films?
- Has the lesion enlarged
- What if there is no interval change?
- Assuming this is a good interval, you can do follow-up imaging or stop
- What if the lesion is enlarging?
- Biopsy it
- What if there are no prior films available?
- Do thin section CT through lesion
- What are you looking for on thin section CT?
- Calcification or fat
- What if there is no calcification or fat?
- Biopsy it, either percutaneously or via bronch
- What if there is fat?
- Presumed hamartoma, and you can stop
- What if there is calcification?
- Must assess what type of calcification
- What types of calcification suggest benign lesion?
-
Diffuse
Popcorn
Concentric (lamellar)
Single central - What types of calcification are indeterminate?
-
Stippled
Single eccentric - What characteristics of a solitary pulmonary nodule need to be assessed?
-
Shape
Size
Presence of spiculations
Edge (Zone of transition)
Satellite lesions
Cavitation
Doubling time - What do satellite lesions suggest?
- Benignity
- What does cavitation suggest?
- Malignancy
- What doubling time suggests benignity?
-
Less than one month
OR
Greater than 2 years - How many criteria are there that can reliably be used to assess a solitary pulmonary nodule as benign?
- Only 3
- What are they?
-
1) Presence of fat
2) Benign types of calcificaton
3) No interval growth for 2 years - What HU is needed to call lesion calcified?
- 200 HU
- What percent of the lesion must be calcified before you can even assess the type of calcification?
- 10%
- What is the exception to the calcification rule?
- Osteosarcoma and thyroid mets can calcify. However, they will be seen in multiplicity. Only consider this if patient has history of one of these diseases.
- What are most solitary pulmonary nodules?
- Granuloma or primary carcinoma
- What are the rest?
- Some are AVMs, and the possibility of this should be assessed before biopsy
- Where are most pulmonary nodules missed?
-
1) Lung apices
2) Central and paramediastinal lungs
3) Superimposed onto ribs and clavicle - What is the differential for solitary pulmonary nodule?
-
Tumor
Inflammation
Other - What percent are inflammation?
- 53%
- What types of inflammation?
- Granuloma from Tb, histo, or coccy
- What percent are tumor?
- 45%
- What types of tumor?
-
Primary CA
Solitary met
Hamartoma - What percent of solitary lung tumors will be primary CA?
- 70%
- What percent of solitary lung tumors will be solitary met?
- 10%
- What percent of solitary lung tumors will be hamartoma?
- 15%
- What are the other 2% of solitary pulmonary nodules
-
Vascular lesions
Congenital lesions
Miscellaneous lesions - What are the vascular lesions that present as nodules?
-
AVM
Pulmonary varix - What are the congenital lesions that present as nodules?
-
Sequestration
Bronchial cyst - What are the miscellaneous causes of solitary nodule?
-
Round pneumonia
Loculated effusion in fissure (pseudotumor)
Mucous plug
Enlarged subpleural node
Silicosis (rare) - What are causes of multiple pulm nodules?
-
Mets
Abscess
Granulomatous lung disease - What varieties of granulomatous lung disease cause multiple pulmonary nodules?
- Infectious and noninfectious
- What are the infectious causes of granulomatous lung disease?
-
Tb
Fungus - What are the noninfectious causes?
-
Sarcoid
Silicosis
Wegener's
Rheumatoid nodules - What if the nodules are small, bilateral, and very numerous?
- Consistent with miliary dz, which has a differential
- What are the causes of miliary pattern?
-
Tb
Certain mets - What are the mets that can do miliary pattern?
-
Thyroid
Melanoma
Breast
Choriocarcinoma - What if the nodules are very small?
- Consistent with nodular interstitial disease
- What is differential for calcified lung nodules?
- Depends on average size of nodules.
- What if nodules are 1 mm or more on average?
-
Tumor
Infection
Silicosis - What tumors calcify?
- Mets
- Which mets?
-
Thyroid CA
Osteosarcoma
Mucinous carcinomas - What are infectious causes of calcified lung nodules?
-
Tb/histo/coccie
Varicella
Schistosomiasis - What about calcified nodules that are very small (on average less than 1 mm?)
-
Metastatic calcification, usually from chronic renal disease
Chronic pulmonary venous hypertension
Alveolar microlithiasis - What is ddx for a large pulmonary parenchymal mass (>6cm)?
-
Tumor (primary or metastatic)
Abscess
Round atelectasis (associated with effusion)
Intralobar sequestration
Bronchogenic cyst
Hydatid disease - What metastatic lesions tend to give big lung mets?
- SCC from head/neck
- What is ddx for a large extrapulmonary mass?
-
Loculated pleural effusion
Fibrous tumor of pleura
Chest wall tumors
Mediastinal masses - When you have a cystic/cavitary intraparenchymal lesion, what is most helpful (but not always) to determine if benign or malignant?
- Wall thickness
- What are criteria?
-
Wall < 2mm thick
Wall 2-15 mm thick
Wall > 15 mm thick - What percent of <2mm are benign?
- 95%
- What percent of 2-15 are benign?
- 50%
- What percent of >15mm are benign?
- <5%
- When the wall is thick, what are you dealing with?
- cyst
- What is the differential diagnosis for cyst?
-
1) Pneumatocele
2) Bulla/bleb
3) Cystic bronchiectasis
4) Congenital cysts
5) Hydatid cyst - What causes pneumatocele?
- Infection or trauma
- What is the difference between a bulla and a bleb?
-
Bulla is intraparenchymal
Bleb is in the pleura - What types of congenital cysts are there?
-
1) Bronchogenic cysts
2) Cystic adenomatoid malformation
3) Sequestration can have cystic elements - What is the differential diagnosis for a lung cavity (i.e. thick walls)
-
1) Abscess
2) Cavitated tumor
3) Cavitated granulomatous mass
4) Cavitated hematoma - What are tumors that can cavitate in the lung?
-
1) SCC (lung or metastatic)
2) Sarcomas
3) TCC of bladder
4) Lymphoma - What is true of cavitated granulomatous masses?
- Usually multiple
- What are the causes of cavitated granulomatous mass?
-
Tb
Sarcoid
Wegener's
Rheumatoid
Fungus (aspergillus) - What entities can have an air crescent sign?
-
1) Invasive aspergillosis
2) Septic emboli
3) Mucor
4) Tb
5) Tumors - How do you analyze small cystic disease of the lung?
- Determine whether the cysts have a true wall or no wall.
- What is the diagnosis of small cystic disease with no cyst wall?
- Emphysema
- What is the differential for small cystic disease with true walls?
-
1) Honeycombing in any end-stage interstitial disease
2) Cystic form of PCP
3) LAM
4) Eosinophilic granuloma - What is the approach to interstitial disease? First
- 1) Type of pattern
- Second?
- Distribution
- 3rd?
- Lung volumes
- 4th?
- Lymph nodes
- 5th?
- Pleural disease
- 6th?
- Evolution of disease
- What is the categorical differential for proximal intraluminal airway mass?
-
Tumor
Inflammatory disease
Foreign body
Mucus plug
Broncholith - What percent of upper airway masses are due to tumor?
- 80%
- What percent of upper airway tumors are benign?
- 25%
- What is the differential for benign tumors?
-
Hamartoma
Papilloma
Hemangioma
Pleomorphic adenoma - What is the differential for malignant tumors?
-
SCC (most common tumor)
Adenoid cystic carcinoma (next most common)
Mucoepidermoid
Carcinoid - What percent of upper airway endobronchial tumors are metastatic lesions?
- 5%
- What tumors tend to invade the trachea from outside?
-
Thyroid
Lung
Esophageal - What is clinical scenario that goes with airway mass?
- Patient undergoing workup for intractable asthma-like symptoms