SPN approach

1. DR. MADHU KIRAN
PG PULMONOLOGY
Solitary Pulmonary Nodule

2. DEFINITION
 Coin lesion
 A solitary pulmonary nodule is defined as a single
discrete pulmonary opacity that is surrounded by
normal lung tissue that is not associated with
adenopathy or atelectasis.
 <3 cms-SPN
 > 3 cms-MASS

3. Features of a spn
 A solitary radiographic shadow does not exceed 3
cm in its largest diameter.
 It may have any contour.
 It may be calcified or cavitated.
 Satellite lesions may be present.
 The lesion is surrounded by air containing lung or,
if it is adjacent to visceral pleura or over the
convexity of the thorax at least 2/3 rds of its
circumference is contiguous to air – containing
lung.

4. INCIDENCE AND PREVALENCE
 CXR-order of 1 to 2 per thousand chest
radiographs
 90 percent are noted as an incidental finding on
radiographic examination

5. D.D of solitary pulmonary nodule
 Malignant tumors
 Benign tumors
 Infectious granulomas
 Non infectious granulomas
 Miscellinious

6. Differential Diagnosis of Solitary
Pulmonary Nodules
Malignant tumors
 Bronchogenic carcinoma (adenocarcinoma, large
cell, squamous, small cell)
 Carcinoid
 Pulmonary lymphoma
 Pulmonary sarcoma
 Plasmocytoma
 Solitary metastases (colon, breast, kidney, head
and neck, germ cell, sarcoma, thyroid, melanoma,
others

7. Benign tumors
 Hamartoma
 Adenoma
 Lipoma

8. Infectious granulomas
 Tuberculosis
 Histoplasmosis
 Coccidiomycosis
 Mycetoma
 Ascariasis
 Echinococcal cyst
 Dirofilariasis (dog heartworm)

9. Noninfectious granulomas
 Rheumatoid arthritis
 Wegener’s granulomatosis
 Sarcoidosis
 Paraffinoma
 Others

10. Miscellaneous
 BOOP
 Abscess
 Silicosis
 Fibrosis/scar
 Hematoma
 Pseudotumor
 Spherical pneumonia
 Pulmonary infarction
 Arteriovenous malformation
 Bronchogenic cyst
 Amyloidoma

11. Contd…..
 Mucoid impaction
 Pleural fibrin ball
 Sequestration
 Simulated pulmonary nodule ( skin tumor , nipple
shadow , rib lesion , foreign body, artifacts )

12. CLINICAL CRITERIA TO
DIFFERENTIATE BENIGN &
MALIGNANT
Clinical benign malignant
age < 35 yrs > 35 yrs
symptoms absent present
Past history&
functional capacity
High incidence of
granuloma,TB
exposure
Smoker , diagnosis
of primary
elsewhere

13. radiographic
benign malignant
size Small ( <3 cm in diameter
)
Large ( > 3 cms )
location No predilection except TB Predominantly upper lobes
(except metastasis )
contour Smooth margins Margins spiculated
calcification Central, laminated ,diffuse
,popcorn
Rare (or) eccentric
calcification
Satellite lesions More common Less common
Serial studies over 2 yrs Stable ( no change) Not stable
Doubling time < 20 or >400 days 30 – 180 days

14. Ct features
benign malignant
calcification Diffuse or central Absent or
eccentric
fat Diagnostic of
hamartoma
Absent
Bubble like
lucencies
uncommon Common in
adenocarcinoma
Enhancement
with IV contrast
< 15HU > 25 HU

15. MALIGNANT SOLITARY
PULMONARY NODULE
Risk factors :
 patient age,
 smoking history,
 nodule size, and
 prior history of malignancy.

16.  Age is one of the most consistent risk factors.
 the incidence of malignancy in
 patients aged 45 to 54 - 63 %
 aged 54 to 64 - 74%
 those above the age of 75 - 96%

17. Smoking
 Average smokers -10 times
 Heavy smokers -20 times higher risk than
nonsmokers

18. SIZE-risk increases with size
 Larger than 3cm - 80-90%
 Smaller than 2cm - 20-60%

19. Growth Rate:
Doubling Time
 Volume = 4/3  r 3
 25% increase in diameter results in doubling of
volume
 Non-malignant disease: less than 20 days or
greater than 400 days
 Malignant lesions: 30 to 180 days

20.  Primary bronchogenic carcinoma is most
common primary malignancy
 A h/o current or prior extra pulmonary malignancy
increase risk
 Mostly of colon,breast,kidney,head and
neck,melanoma,sarcoma etc..

21. BENIGN SPN
 These are more common in young and non
smokers.
 Hamartomas ; most common
 are developmental malformations
 Contains cartilage,fibromyxoid stroma,adipose
tissue
 Incidence- >70 years, equal in both sexes
 Average size -1.5 cm, mostly asymptomatic

22. Infectious granulomas; >90% of benign spn
 most common ; histoplasmosis
, coccidiomycosis,
tuberculosis
 clues like h/o travel, residence, occupation are
useful

24. Benign Calcifications

26. Benign Calcification:
Popcorn Calcification

27. Benign Calcification:
Central Calcification

28. stippled or eccentric patterns
have been associated with cancer

29. Work-up of SPN:
Imaging and Procedures
 CXR
 CT Scan
 PET Scan
 Bronchoscopy
 Biopsy
 TTNA, FNA
 VATS, Open

30. Imaging techniques
PLAIN X-RAY CHEST
 Mostly discovered routinely while asymptamatic
 PA,lateral views are must
 a nodule of same size for 2 years is benign
 Digital x ray can improve detection

31. COMPUTED TOMOGRAPHY
 Indications;1) assessing indeterminate nodules
<3cm 2)staging of
larger lesions 3)evaluating accessibility for
biopsy or resection
HRCT more useful in determining calcification
patterns, .
 nodules of density >185 hf -benign
<185 hf - indeterminate
Nodules may be characterized as
 SOLID,
 PARTLY SOLID ,
 GROUND GLASS opacities

32.  Edge charcteristics of nodules can offer insight
into whether lesion is benign or malignant

33.  Benign lesions are often well circumscribed with
round appearance
 Malignant nodules tend to have irregular or lobulated
borders
Ct characters s/o malignancy :
 Spiculated margins
 Pleural retraction
 Feeding vessel sign
 Vascular convergence
 Dilated bronchus leading into nodule
 Cavitations

34. Nodule –lung interface ;
 1) spiculated appearance s/o malignancy
 2)plural tags seen in 60-80% of peripheral
malignancies
Air bronchogram; -in lung malignancies
- focal air collections,
- common in bronchoalveolar carcinomas.
Nodule enhancement-CT; <15 hf enhancement is
benign

35. Spiculated margins

36. Corona radiata like margins

37. Air bronchogram

38.  The superior resolution of multidetector scanners
has also facilitate the development of
VOLUMETRIC CT
 Allow growing lesions to be identified earlier than
conventional transverse ct
 Three dimensional volume analysis enabled
tumor growth to be detected in 5mm nodules as
early as 30days after initial ct
 Ct volume doubling time <400days or a new solid
component in a previously nonsolid nodule was
defined POSTIVE (nelson trial)
 Sensitivity and specificity is high.

39. POSITRON EMISSION TOMOGRAPHY;
malignant cells have increased uptake and
metabolism of glucose
 18 flouro deoxy glucose is used
 Less useful in <8mm nodules
 False -ve ; in broncho alveolar carcinoma,
carcinoids,
mucinous adenocarcinomas
 False +ve ;tuberculosis, endemic
mycosis,rheumatoid arthritis, sarcoidosis,
uncontrolled hyperglycemia

40.  Integrated PET-CT scanners allow more precise
anatomic localization of areas of FDG uptake
than PET imaging alone
 PET imaging also provides information regarding
lung cancer staging since it will detect
unsuspected distant metastasis.

41. Risk factors associated with a low probability of
malignancy
include
 diameter less than 1.5 cm,
 age less than 45 years,
 absence of tobacco use,
 Having quit for 7 or more years,
 and a smooth appearance on radiography

42. Risk factors associated with a moderately
increased risk of malignancy include
 diameter 1.5 to 2.2 cm,
 age 45to 59,
 smoking up to 20 cigarettes per day,
 being a former smoker within the last 7 years
 a scalloped edge appearance on radiograph

43. Risk factors associated with a high risk of
malignancy include
 a diameter of 2.3 cm or greater,
 age greater than 60 years,
 being a current smoker of more than20 cigarettes
per day,
 a history of prior cancer
 Corona radiata appearance on radiograph

46. Biopsy techniques
 Bronchoscopy; has limited usefulness
 Nodules in inner or middle 1/3 has high yield
 Less sensitive for smaller lesions

47.  The presence of type 1 and type 2 , a bronchus
leading to or contained within the body of mass or
nodule on CT, has been subsequently termed as
POSITIVE BRONCHUS SIGN
Newer bronchoscopic techniques include
 Electromagnetic navigation and guidance EMN
 Radial endobronchial ultrasound EBUS
 Ultrathin bronchoscopy
 Guide sheath techniques
 Virtual bronchoscopic navigation

48.  Tsuboi and colleagues
described four types of
tumor–bronchus
relationships:
 (1) the bronchial lumen is
patent up to the tumor;
 (2) the bronchus is
contained in the tumor
mass;
 (3) the bronchus is
compressed and
narrowed by the tumor,
but the bronchial mucosa
is intact; and
 (4) the proximal bronchial
tree is narrowed by
peribronchial or
submucosal spread of the
tumor or by enlarged

49. Percutaneous needle aspiration
 useful in outer 1/3 ,has high yield
 Complication is pneumothorax
Contraindications;
 1)fev1 <1litre
 2)bulla in needle path
 3)bleeding diathesis
 4)post pneumonectomy

50. Work-up of SPN:
CT guided TTNA
 Increasing utilization of TTNA
 Not indicated for patients committed to
surgery
 Accuracy for detecting malignancy 64-100%
 Yield increased when cytopathologist present
 Three results:
 Malignant
 Specific benign, e.g. TB
 Non-specific benign, e.g. bronchoalveolar
hyperplasia

52. Work-up of SPN:
CT guided TTNA
 Complications:
 Pneumothorax 25%, chest tube <5%
 Hemoptysis <10%
 Relative contraindications:
 Pulmonary HTN, severe COPD, AVM’s, coagulopathy
 Absolute contraindication:
 One lung or bilateral lung transplant

53.  Thoracotomy , mortality of 3 to 7 percent
 Lobectomy using either open thoracotomy or
video-assisted thoracoscopic surgery with
lymph node resection and staging,remain the
standard of care for stage I bronchogenic
carcinoma.

57. Diagnostic approach
 1)On discovery : determine whether it is true
SPN,is spherical,is located in lung fields. CT
should be part of initial investigation.
 2)Thorough history should be taken.
 3)All prior x-rays,CT, should be compared with
present.
 *if nodule unchanged for 2years no further follow
up
 *if doubling time <18 months –malignant >18
months-indeterminate.

58.  4)estimate probability of malignancy
 Low probability <10% -
 benign calcification pattern , age <35 , stable for
2years, can be observed
with serial CT scans

59.  High probability : for surgery
staging followed by VATS /Thoracotomy
 PET scan useful for staging
 Even if PET negative : biopsy or resection done

60.  Moderate probability : (10 -60% risk).
 After evaluation of x-ray & CT - 70-75%
indeterminate are malignant
 PET scanning for those with nodules measuring 1
cm or greater in size .
 Transthoracic fine-needle aspiration,
 bronchoscopy if there is an air-bronchus sign, or
a contrast-enhanced CT are reasonable options.
 If the results are positive, then surgery is clearly
warranted

61. Thank you