the lecture approaches the problem of solitary pulmonary nodule in terms of variable imaging findings,differential diagnosis and algorithm of follow up .

1. The problem of Solitary
pulmonary nodule
Dr/Ahmed A. Bahnassy
Consultant radiologist
(MBCHB-MD-FRCR (London –UK

2. DD of Solitary pulmonary nodule

3. SPN
 Ii is defined as a focal opacity ,visible on chest
radiograph or CT ,with the following criteria :
1.Relatively well defined .
2.Surrounded-at least partially - by lung .
3.Roughly spherical in shape.
4.3 cm or less in diameter (more than 3 cm is
termed mass )

5. Clinical evaluation
 Hx of smoking.
 Age over 40.
 Occupational exposure.
 Lung fibrosis.
 COPD.
 Family Hx of Lung cancer.
 Travel History
 TB skin test.
 Other diseases (Rheumatoid arthritis )
 Malignancy .(solitary metastasis or increased likelihood of 1ry
bronchogenic Ca for H & N breast ,bile ducts ,oes. ,cervix
,bladder ,prostate ,etc up to 3 folds )

7. Radiographic evaluation
 Morphological Characteristics.
 Density.
 Growth rate .

8. I-Morphological Characteristics
 Size : Diameter Malignancy
The likelihood of rate
malignancy is directly 1cm> 35%
related to size reaching
more than 85 % for SPN
more than 2 cm . cm 1-2 50%
cm 2-3 80%

9.  Location :
2/3 of lung cancers occur in upper lobes.
60% seen in lung periphery .
Only 10 % seen in medial third .
Mets tend to be subpleural or outer 1/3 of
lung.
2/3 of mets are in lower lobes.

10.  Edge Appearance :
90% of lesions with irregular or spiculated edges
are malignant.
20% only of well defined lesions are malignant
(e.g.: Mets or carcinoid tumor )
Corona Maligna or radiata represent either
desmoplastic reaction around the tumor or
actual invasion of surrounding lung …common
with BAC and adenocarcinoma

11. Carcinoma
Focal scarring
Brncioalveolar cell carcinoma

12. Pleural tail in adenocarcinoma
Pleural tag refers to linear density (fibrosis)
extending to pleural surface .

13. Pleural tag in adenocarcinoma

14. Granuloma
Hamartoma
.Metastasis

15. Benign lesion-smooth edges

16. Mets

17. Hamartoma

18. Halo sign
 Halo of ground glass opacity surrounding a
nodule .
Commonly present in Leukemic patient with
invasive aspergillosis (represent hemorrhagic
infarction )
Can occur with any other infections .
Can be seen with BAC and adenocarcinoma
(representing lepidic growth )

19. Causes of Halo sign
Invasive aspegillosis
.Wegener Granulomatosis
.BAC
.Kaposi sarcoma
.Mets
.TB, nocardiosis
.CMV infection
PCP
BOOP

20. Invasive aspergillosis

21. BAC

22.  Shape :
Lung Ca tends to be irregular , lobulated or
notched.
Granuloma are rounded.
Hamartoma and metastasis are round ,oval or
lobulated.
Scars , atelectasis may appear linear .
AVM and mucous plugs are particular in shape

23.  Air bronchogram and pseudocavitation.

24.  Cavitation

25.  Air crescent sign

26.  Air-Fluid level

27.  Satellite nodules ..GALAXY sign

28. Feeding vessel sign
Showing a vessel ending into and feeding a lesion
Associated with infarction ,AVM , metastasis
,septic emboli .

29. II-Density
 Ground Glass opacity

30. Calcification
Causes

31.  Benign Vs malignant patterns of calcifications

32.  Bull eye calcification

33. Target calcification -Histoplasmoma

34. POP corn calcification -hamartoma

35. Eccentric calcification in adenoCa

36.  Water density

37.  Fat density

38. Contrast enhancement
HRCT –Malignant looking  Increase 40 HU (>15 )
mass post contrast. .typical of
malignancy (77%
accuracy)

39.  Contrast opacification
AVM
Pulmonary vein varix.
Pulmonary artery aneurysm

40. III-Growth
 Doubling time is the time required for a lesion
to double its volume .
 26% increase in nodule diameter is one doubling
 Doubling of diameter is 3 volume doublings.
 Range of doubling time of carcinomas is 1
week to 16 months.
 Doubling time <1 month or >200 days is likely
to be benign .
 No growth over 2 years most likely benign.

41. ?How to evaluate
.See prior examinations
If not available
Small lesions follow up is at 3,6 months ,1 and 2
.year
Very small lesions (3mm)..yearly follow up

43. SPECT & PET Scan additions
 Using FDG high activity in PET is associated
with malignancy

44. .Biopsy taking
 FOB =fiber optic
bronchoscopy..for central lesions.
 TNB =Trans thoracic needle
biopsy ..For peripheral lesions.

45. Strategy for nodule evaluation