Pulmonary Nodule
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Transcript of Pulmonary Nodule
Solitary Pulmonary Nodule
Solitary Pulmonary NoduleUp to 150,000 discovered each yearUsually detected incidentallyDefined as:
Single Surrounded by and within normal pulmonary
parenchyma <3cm=nodule >3cm=mass
Major question: Is the nodule benign or malignant?
Differential – Benign (70%)Infectious Granuloma (80%)
Histoplasmosis, Coccidioidomycosis, mycobacteria
Hamartoma (10%) Slow growing, “popcorn” calcification,
heterogeneous (fat, muscle, calcification)Inflammatory
Wegener’s, Rheumatoid noduleVascular
Differential – Malignant (30%) Primary lung malignancy
*Adenocarcinoma peripheralLarge Cell peripheralSquamous Cell central
Carcinoid tumorsCentral > peripheral
Lung metastasisMelanoma, sarcoma, colon, breast, kidney,
testicleOften present as multiple nodulesIn a person with h/o cancer, a SPN on CXR has a
25% probability of being a metastasis
Pulmonary Nodules51% of smokers 50 years and older have
pulmonary nodules on CT.Since only a small number of these are
malignant, how do we manage them?In the past, we use to closely monitor all
nodules for at least 2 years to confirm stability.Unnecessary surgery and biopsies have
potential morbidity and mortality.Unnecessary imaging increases healthcare
costs
Fleischner Society Guidelines
Fleischner Society Guidelines
The Fleischner Society is an international, multidisciplinary medical society.
Experts in adult and pediatric radiology, pathology, pulmonary medicine and thoracic surgery.
2005 Consensus Statement MacMahon et al. Radiology
2005;237:395-400
Pulmonary Nodules
Definition Spherical, well circumscribed pulmonary opacity that
measures <3cm in size >3cm is a lung mass
Guidelines are primarily based on the size of nodule and risk factors for malignancy
Size Fewer than 1% of nodules <5mm are malignant. 18% of nodules 8-20mm are malignant. 50% of nodules larger than 20mm are
malignant.
Pulmonary Nodules
Risk Factors Smoking
Lung cancer is 10 times more common in smokers compared to non-smokers
History of lung cancer in a first degree relative
Exposure to asbestos, uranium and radon.
Rare in under 35 years of age
Fleischner Society Guidelines
Management Considerations
Appearance Spiculated nodules have a higher risk Ground glass nodules can be low
grade cancers and grow slower Calcifications favor benignity Clustered nodules favor an infectious
process
Patients with Known Primary Malignancy
Management is typically based on the specific clinical situation and the relevant treatment protocol.
Makes patient management difficultCan’t assume that a nodule is malignant.No general guidelines established, but
frequent close follow up is usually indicated.Larger nodules may require PET or biopsy
Approach to SPN Goal is to remove all malignant nodules
while avoiding resection of benign nodules5yr survival is 70-80% in patients with Stage
1a NSCLCa that is resected Determine the probability of malignancy
Clinical factorsCharacteristics of the nodule on imaging
Chose management based on probability of malignancy
Clinical FeaturesSmoking historyAgeExposure to asbestosFamily HistoryPreviously diagnosed cancer
Age Probability the SPN is Malignant
35-39 3%40-49 15%50-59 43%>60 50%
Radiographic Features Size
Larger size associated with higher likelihood of malignancy 3mm associated with 0.2% risk VS 20mm associated with
50% risk of malignancy Border
Malignant: spiculated (corona radiata sign), scallopedBenign: smooth
DensityIncreased density argues against malignancyIn one study, SPNs <147 Hounsfield units were malignant
whereas SPNs >164 Hounsfield units were benignNo clear number to say what is benign and malignantRarely used a part of routine evaluation
Radiographic Features - Growth Malignant lesion doubling time is b/t 20-400 days Benign lesions either grow very quickly (infectious) or
remain stable for a prolonged period of time (hamartoma)
Traditionally there has been a “2yr rule” where if there is no growth at 2 yrs, it is considered benignRecent studies have challenged this rule○ 156 SPNs and masses from 1-14cm in size○ 74 of these cases had previous films for comparison
In 26 cases, there was documentation of no growth, yet 9 of these nodules/masses were found to be malignant
○ Advise to interpret 2 yr stability with caution Bronchoalveolar Cell Ca and carcinoid often grow
slowly Monitor growth with CT, not x-rays
Radiographic Features Ground Glass Appearance
Associated with malignancyOften associated with slow growing
bronchioloalveolar carcinoma Calcification
Suggests benign lesion○ Granuloma: laminated or central pattern○ Hamartoma: “popcorn” pattern, focal areas of fat and
calcification (“areas of very high and very low attenuation”)
Malignant calcification: stippled, eccentric (asymmetric)
1. Corona radiata (spiculated)2. Scalloped border3. Air bronchus sign4. Smooth, well-marginated nodule, dense central calcification typical
of histoplasmosis5. Central calcification and laminated fibrous tissue 6. Calcification and fat, typical of a hamartoma
**Images from UTD and NEJM
Initial ManagementDetermine the probability of
malignancy based on: Clinic factors Radiographic features
Ost D et al. N Engl J Med 2003;348:2535-2542
Assessment of the Risk of Cancer in Patients with Solitary Pulmonary Nodules
Management Low Probability
Follow with serial CT scans [Fleischner society criteria]
Traditionally q3 months X 4 q6 months X 2 Intermediate Probability
< 1cm serial CT scans> 1cm PET○ If negative serial CT scans○ If positive excision
High ProbabilityExcision
CT-ScansIn general, if a SPN has been stable
for 2 yrs, it is likely benign Certain types of malignancy are
notorious for slow growthCarcinoid, bronchioloalveolar
Interval f/u with CT scan depends on size and risk for cancer
Size Risk of Malignancy
Interval Follow up
<4mm LowHigh
None12 months
4-6mm LowHigh
12 months6-12 then 18-24 months
6-8mm LowHigh
6-12 then 18-24 months3-6 then 6-12 then 24 months
>8mm Low or High 3, 6, 9, and 24 months
Metabolic Imaging FDG-PET scan (18-
flourodeoxyglucose)Metabolically active cells take up the
FDG more readilyUsed for patients with nodule >1 cm
who have an intermediate probabilityAdditional advantage: staging
PET-Scan95% sensitivity, 78% specificityFalse Positives:
Infectious or inflammatory processesFalse Negatives:
Nodules with low metabolic activity:Bronchioloalveolar tumors, carcinoid tumors Small lesions (<1cm)
Nodule SamplingThrough the airway:
BronchoscopyThrough the chest wall:
Percutaneous needle aspiration Percutaneous needle biopsy
Decision depends on: size, location, local expertise
Bronchscopy Good for central nodules
Air bronchus sign Poor for small, peripheral SPNs At its best, sensitivity is only 70%
CT showing bronchus leading to lesions ; “air bronchus sign”
Specimens collected by washings, lavage or direct sampling
Several techniques being studied for futureEndobronchial U/S with fluoroscopyCombining FISH with cytology
Percutaneous needle aspiration or biopsy Diagnostic yield is about 90%
Up to 97% when biopsy is performed Better for evaluating small SPNs
Verses bronchoscopy Aspiration obtains material for cytology Biopsy obtains core tissue
Evaluates architectureBetter for diagnosing benign nodules
Complications: pneumothorax, bleeding
Surgical ResectionIndicated if:
Likelihood of malignancy is high Positive PET Scan Percutaneous sampling proved malignancy
Done via VATS or thoracotomyVATS has replaced thoracotomy in
many cases, especially for nodules close to the pleura
-Low probability: -Serial CT scans-Intermediate probability: -Serial CT scans (<1cm) vs PET (>1cm)-High probability: -Excision
Low Intermediate HighDiameter of Nodule (cm)
<1.5 1.5-2.2 >2.2
Age <45 45-60 >60
Smoking status Quit >7yrs ago
Quit < 7yrs ago Never quit
Nodule margins Smooth Scalloped Spiculated
Key Points SPN: a single lesion both within and
surrounded by pulmonary parenchyma Malignant (30%) or Benign (70%)
Malignant: bronchogenic carcinoma, carcinoid tumor, metastasis
Benign: infectious, inflammatory, hamartoma Determine likelihood of malignancy
Clinical factors, radiographic features Once likelihood of malignancy is
determined, you can determine initial management
Key Points Low probability: serial CT scans Intermediate probability: serial CT scans
(<1cm) vs PET (>1cm) High probability: Excision CT scans preferred to X-rays for serial imaging Nodule sampling done through: bronchoscopy,
percutaneous aspiration or biopsy Definitive intervention is excision by VATS or
thoracotomy
Solitary Pulmonary NoduleBasic strategy is to identify
malignant versus benignDefinition: Opacity with diameter <
3cmLarger lesions are called massesIt occurs in 1 every 500 CXR
Nodules prove to be malignant in 40% of cases
Most often Bronchogenic carcinomaMost common benign is hamartomaBenign lesions: rheumatoid
granuloma, healed infarct, pulmonary anurysm, Wagner’s granulomatosis
Solitary Pulmonary Nodule
Early ResectionStudies have proven that early resection
results in 5-year survival rate of 50%If nodule is 1cm or less rate is about
80%Survival rate after discovery of
bronchogenic carcinoma is 15% and hence the importance of early discovery in terms of cure
Growth of a NoduleMalignant nodules grow at a
constant rate expressed as doubling time
This usually falls between 25 and 450 days with a median of 120 days
An increase of 28% in nodule diameter indicates doubling
Benign lesions grow slowly with doubling time exceeding 500 days
It is almost conclusively a benign lesion if size is stable for 2 years ( doubling time exceeding 720 days )
A doubling time of less than 20 days signifies inflammatory process
Growth of a Nodule
CalcificationRadiographic pattern of calcium
deposition is helpful Benign lesions tend to have central,
laminated (bull’s eye), diffuse or popcorn pattern
Malignant lesions have speckled or eccentric pattern
High Resolution CTHRCT is the most sensitive and
specific for assessing the size, shape, calcification and edge of a nodule
Type 1 Type 2 Type 3 Type 4
PET ScanHighly valuable noninvasive toolIt is 95% sensitive for identifying
malignancy and 85% specific False positive results may occur in
lesions that contain active inflammatory tissue (histoplasmomas)
BiopsyBx has a high yeild in establishing DxBronchoscopy can not access a
nodule if it is peripheral and smallIf CT shows a bronchus entering a
nodule its yeild is much higherTransthorathic needle aspiration
(NAB) has a sensitivity of 80% to 90%
SurgeryThoracotomy to resect a malignant
nodule carries significant death of 3% to 4% but for a benign lesion it is 0.3%
Thoracoscopy carries less significant morbidity and lessens hospital stay
It is not known if the 5-years survival is different between the two approaches
Benign vs MalignantAge <48nodule diameter<1.5never smokednodule edge type1doubling time >500 dcalcification in benignNeedle Bx: benign dis
Needle Bx: Nonspecific
>48>1.5ever smokedtype330 to 400 daysindeterminate
patternmalignant diseasesuspicious cells
Review all prior CXRGet CT scansIf probability of cancer is <10% wait
and watchIf it is high thoracotomy should
interveneBronch & NAB reserved for pt who are
reluctant to go for surgery before Dx
Decision Making
If results are intermediate: Thoracotomy, NAB and PET are equal in terms of 5-years survival
PET is slightly more effective,noninvasive
If PET is +ve but other criteria are low for malignancy, then ANB is needed to R/O infectious granulomas
Decision Making
CASE1 -
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CASE1 -asbestosis
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Case-2 nodule Lung
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Case-2- Cacified nodule -breast
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Case-3
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Case-3- Pulmonary HAMARTOMA-fairly well-defined PN in the right mid zone associated with a central nidus and a laminated calcification in a pulmonary hamartoma
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Case-4
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Popcorn calcification in Hamartoma
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Case-5 ct scan Low attenuation in nodule
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Case-5-Hamartoma-ct scan Low attenuation in nodule
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Case- 6
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Case- 6-multiple small calcific PNs due to old healed histoplasmosis
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Case 7 [ 5 YEARS APART CXR]
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Case 7 [ 5 YEARS APART CXR]
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wo chest radiographs 5-years apart showing a high-density solitary pulmonary nodule remaining unchanged over a 5-year period. One of the most reliable imaging features of a benign lesion is as a benign pattern of calcification and periodic follow-up with CT showing no growth for 2 years. The high density of the well-defined nodule suggest that this is calcified granuloma and no further follow-up is indicated except in patients with calcium producing tumors such as a primary osteosarcoma , medullar ca thyroid mets
Case 10
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Case 10 --old healed TB. Note the loss of lung volume/fibrosis in the right upper zone and the associated pleural calcification due to a previous tuberculous empyema. Calcific granulomas are also noted in the left apical region
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Case 8
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Case 8-calcification at both the lung apices associated with a right lower paratracheal calcified lymph node due to healed tuberculosis
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Case 11
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Case 11 -dense nidus of central calcification in an adenocarcinoma of the lung
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Case 15 -
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Case 15 -shows a central pulmonary carcinoid associated with dense amorphous calcification (arrow)
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case 22
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case 22 -a large PN at the right lung base with central high density due to calcification in a metastatic deposit from a leiomyosarcoma of the uterus
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case 24
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case 24 - multiple high-density lung masses in a patient with a nonmucinous adenocarcinoma of the sigmoid colon
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Differential Diagnosis Of Multiple Pulmonary Nodules Metastatic Rumors Infectious Granulomas Rheumatoid Nodules Sarcoidosis Metastatic Pulmonary calcification Amyloidosis Chronic hypersensitivity pneumonitis Bronchiolitis –associated interstitial lung disease Lymphoid Interstitial Pneumonia Infections[ e.g., viral, granuloma] Pulmonary Hyalinizing granuloma Malignancy[e.g. Multifocal adenocarcinoma