This document discusses solitary pulmonary nodules (SPNs), which are round or oval lung opacities smaller than 3 cm surrounded by lung tissue. Common causes of SPNs include infections, inflammation, congenital abnormalities, airway diseases, vascular lesions, and neoplasms. Imaging with CT scan is important to evaluate characteristics like size, shape, margins, growth, calcification patterns, air bronchograms, and enhancement which provide clues to differentiate benign from malignant SPNs. PET scanning also helps but has limitations. The Fleischner Society guidelines provide recommendations on follow-up and management of indeterminate pulmonary nodules found incidentally on CT scans.

1. SOLITARY PULMONARY NODULE
Presenter:Dr.Vishwanath patil

2. DEFINITION:
• A solitary pulmonary nodule (SPN) is a round or oval opacity
a. Smaller than 3 cm in diameter that is completely surrounded
by pulmonary parenchyma.
b. Not associated with lymphadenopathy.
c. Not associated with atelectasis, or pneumonia.

4. D/D of SPN
1.INFECTIVE CAUSES:
A. GRANULOMA
B. MYCETOMA.
C. ASPERGILLOMA.
D. ECHINOCOCCUS/HYDATID CYST.
E. FOCAL ROUND PNEUMONIA.
F. LUNG ABSCESS.

5. D/D of SPN
2.INFLAMMATORY:
A. RHEUMATOID NODULES.
B. SARCOIDOSIS.
C.WEGENERS GRANULOMATOSIS.

6. D/D of SPN
3. CONGENITAL:
A. BRONCHOGENIC CYST
B. CCAM
C. INTRAPULMONARY LYMPH NODE
D. SEQUESTRATION
4. AIRWAY AND INHALATIONAL DISEASE:
A.MUCOID IMPACTION
B. BRONCHIAL ATRESIA
C. CYSTIC FIBROSIS
D. PROGRESSIVE MASSIVE FIBROSIS
E. LIPOID PNEUMONIA

7. D/D of SPN
5.VASCULAR LESIONS:
A. HEMATOMA
B. INFARCTION
C. PULMONARY ARTERY ANEURYSM
D. PULMONARY VEIN VARIX
E. ARTERIOVENOUS FISTULA
F. SEPTIC EMBOLISM

8. D/D of SPN
6.Neoplasms
BENIGN AND NEOPLASM LIKE
CONDITIONS
MALIGNANT
A. HAMARTOMA. A. CARCINOMA.
B. ENDOMETRIOMA. B. LYMPHOMA.
C. MESENCHYMAL TUMOR. C. LYMPHOPROLIFERATIVE DISEASES.
D. SOLITARY METASTATIC NEOPLASM.
E. BRONCHIAL CARCINOID.
F. SARCOMA.

9. D/D of SPN
• SPURIOUS LESIONS ON CXR
• NIPPLE SHADOW
• PLEURAL BASED LESIONS
• CHEST WALL LESIONS
• SKIN NODULES
• ARTIFACTS DUE TO CLOTHING
• SCREEN ARTIFACTS
Benign granuloma and primary bronchogenic carcinomas account for 80% of
cases of SPN.

10. IMAGING OF SPN
1.CHEST RADIOGRAPH.
2. CT SCAN.
3. MRI.
4. FDG-PET / SPECT.

11. CT: Benign versus malignant
• Size.
• Shape.
• Margin.
• Growth.
• Calcification.
• Air Bronchogram sign.
• Solid and Ground-glass components.
• Contrast enhancement.

12. CT: Benign versus malignant
• SIZE:
• 20-30mm-80% chance of malignancy.

13. CT: Benign versus malignant
• Shape:
MALIGNANT: IRREGULAR/LOBULATED/NOTCHED Lobulation
occurs in 25% of benign nodules.
BENIGN : ROUND/OVAL/SMOOTH (SCARS/AREAS OF
ATELECTASIS MAY APPEAR LINEAR OR ANGULAR).

14. CT: Benign versus malignant
• Shape:
-Japanese screening studies
showed that a polygonal shape
and a three-dimensional ratio
> 1.78 was a sign of benignity.
-The three-dimensional ratio is
measured by obtaining the
maximal transverse dimension
and dividing it by the maximal
vertical dimension.

15. CT: Benign versus malignant
• Margin
• Corona radiata sign -
highly associated with
malignancy (figure)
• Lobulated or scalloped
margins - intermediate
probability
• Smooth margins - more
likely benign unless
metastatic in origin

16. CT: Benign versus malignant

17. CT: Benign versus malignant

18. CT: Benign versus malignant
• Growth
• Comparison with prior imaging studies is often the most
useful procedure to determine the importance of the finding
of a SPN.
• Stability
• Solid – 2 years.
• Subsolid – 3 years.
• Malignancy doubling time-20 to 400days
• Very rapid, or slow- less likely to be malignant.

19. CT: Benign versus malignant
• Calcification
a.Diffuse,
b.Central,
c.Laminated or popcorn
calcifications are benign
patterns of calcification.
• These types of
calcification are seen in
granulomatous disease
and hamartomas.

20. CT: Benign versus malignant

21. CT: Benign versus malignant

22. CT: Benign versus malignant
• Calcification
a.Reticular
b.punctate
C.eccentric
d.amorphous.

23. CT: Benign versus malignant

24. CT: Benign versus malignant
• Air Bronchogram sign
• Recent studies have
showed that an air
bronchogram is more
commonly seen in
malignant pulmonary
nodules.
It is most commonly seen
in BAC (bronchoalveolar
cell carcinoma) and
adenocarcinoma.

25. CT: Benign versus malignant
• Solid and Ground-glass components
• Another result from screening
studies is that nodules containing a
ground-glass component are more
likely to be malignant .
• Partly solid lesions with ground-glass
components had a malignancy rate
of 63%.
• Nonsolid - only ground-glass lesions
had a malignancy rate of 18%.
• Only solid lesions had a malignancy
rate of only 7%.

26. CT: Benign versus malignant
• Contrast enhancement less than 15 HU has a very high
predictive value for benignity (99%).
After a baseline scan, 4 consecutive scans at 1 minute
interval are performed.
This applies only for nodules with the following selection
criteria:
• Nodule > 5mm
• Relatively spherical
• Homogeneous, no necrosis, fat or calcification
• No motion or beam hardening artifacts

27. PET-CT: benign versus malignant
• PET-CT plays an increasingly important
role in the evaluation of solitary nodules.
• When you perform PET-CT, you have to
realize the following:
1. PET has a very high sensitivity 95%, but
a lesser specificity of only 81%
2. PET is false positive in granulomatous
disease
3. PET is usually false negative in size
• With these specificity numbers, there
will be false positives in about 20%,
depending on the background
prevalence of granulomatous disease.
On the left a patient with an
adenocarcinoma, that was not
hypermetabolic on the PET, so it is a
false negative PET.

28. The Fleischner Society pulmonary
nodule recommendations (2017)
• Pertain to the follow-up and management of
indeterminate pulmonary nodules detected incidentally on CT
and are published by the Fleischner Society.
• The guideline does not apply to lung cancer screening,
patients younger than 35 years, or patients with a history of
primary cancer or immunosuppression.

29. The Fleischner Society pulmonary
nodule recommendations

30. The Fleischner Society pulmonary
nodule recommendations

31. The Fleischner Society pulmonary
nodule recommendations

32. The Fleischner Society pulmonary
nodule recommendations

33. • Thank you