solitary pulmonary nodule

2. A solitary pulmonary nodule
(SPN) is a round or oval opacity
smaller than 3 cm in diameter that
is completely surrounded by
pulmonary parenchyma and is not
associated with lymphadenopathy,
atelectasis, or pneumonia.

3.  SPN is found in 1-2% of all CXR
 Geographic variations in the incidence of
benign lesions, especially infectious
granulomas
 No sex difference in incidence
 Solitary nodules can occur at all age

4.  Smoking history
 Prior history of malignancy
 Travel history - Travel to areas with endemic
mycosis (eg, histoplasmosis,
coccidioidomycosis, blastomycosis) or a high
prevalence of tuberculosis
 Occupational risk factors for malignancy -
Exposure to asbestos, radon, nickel,
chromium, vinyl chloride, and polycyclic
hydrocarbons
 Previous history of tuberculosis or
pulmonary mycosis

5. Congenital Traumatic
Bronchogenic cysts hematoma
AVM (congenital arteriovenous malformations)
Bronchial atresia
Infective Neoplastic
TB, round pneumonia Bronchogenic ca.
Fungal Carcinoid
Hydatid Plasmacytoma
Abscess Metastases
Miscellaneous Lymphoma
Wegeners granulomatosis Adenoma, hamartoma
RA
Amyloidosis ARTEFACTS
Rounded atelectasis

6.  40% of spn are malignant, with other common
lesion being granuloma and benign lesion
 Benign
 80% infectious granulomas
 10% hamartoma
 10% non-infectious granulomas, benign
tumours
 Malignant
 25% metastatic
 75% bronchogenic carcinoma and carcinoid

7. Extra thoracic artefacts
 Cutaneous masses – nipple, lipoma ,NF
 Bony lesions – island, healing #, sclerotic lesion
 Pleural tumors / plaques
 Encysted pleural effusion
 Pulmonary vessels

8.  PLAIN radiography
 CT
 NCCT, CECT
 PET WITH FDG-F18
 PET- CT
 FNAC / BIOPSY

9. TWO ISSUES
Lesion detection
Lesion characterization
benign versus malignant

10.  Pick up depends upon experience
 Over reading/ under reading
 High Kv – better rate of detection
 Digital radiographs- allow manipulation on a computer
monitor
Always compare current radiographs
with previous radiographs

11.  SPNs are discovered first as incidental findings on chest
radiographs
 The first step is to determine whether the nodule is
pulmonary or extra pulmonary
 A lateral chest radiograph, fluoroscopy, or CT of the chest
often helps determine the location of the nodule
 >8-10 mm Nodules are identifiable by chest radiographs
 Occasionally, SPNs can be visualized at 5 mm in diameter

13.  Size
 Margin
 Calcification
 Fat
 Cavitation
 Air bronchograms or bubbly lucencies

14. SIZE
The size of the mass is of little diagnostic value
Only a small percentage of nodules under 1 cm
in diameter are malignent.

15. MARGIN
 Small nodule with smooth margin suggestive of benign
but not diagnostic of benign lesion
 Lobulated contour
 Irregular margin typical malignant lesion
 Spiculating margin
 Adjacent tiny nodules, called satellite nodules, may mimic
the appearance of a lobulated and the presence of these
nodules is strongly associated with benign nature

18.  Suggestive of benign SPN
 – Central, solid
 – Laminated
 – Popcorn -1/3 rd of hamartoma
 – Diffuse
 Suggestive of Malignant SPN
 – 6-14% of malignant nodules are calcified on CT
 – Eccentric
 – Stippled

19.  A stippled appearance or psammomatous calcification
can be seen in SPNs that are metastases from mucin-
secreting tumours such as colon or ovarian cancers
• Dense foci of calcification or be entirely calcified,
with a pattern resembling that of benign Disease can be
seen in carcinoid, metastatic osteosarcoma and
chondrosarcoma

20. Central = granuloma
Nodule completely calcified = granuloma
Target = histoplasmosis
Popcorn = hamartoma

21. ECCEN

23.  SPNs with irregular-walled cavities thicker than 16 mm tend to
be malignant
 Benign cavitated lesions usually have thinner, smooth wall
 Up to 15% of lung cancers form a cavity, but most are larger
than 3cm in diameter

24. THICK WALLED THIN WALLED

25.  Air bronchograms are seen more commonly in
pulmonary carcinoma than in benign nodules
 Air bronchograms were seen in approximately
30% of malignant nodules but in only 6% of
benign nodules
 Air bronchograms is due to desmoplastic reaction
to the tumour that distort the airway

26.  50% of hamartomas have fat
 30% of hamartomas have calcification (popcorn
appearance)
 Middle-aged adults, slow growth ,90% in intra pulmonary
and within 2cm of pleura
 fat is present in the nodule , hamartoma or lipoma
become most likely cause , Metastasis from lipo sarcoma,
RCC, may occasionally contain fat
 In patient without prior malignancy, focal attenuation
(-40to-120) is reliable indicator of hamrtoma.

28.  tuberculoma:
 most common in upper lobe
 well defined and lobulated ,
 calcification frequent , 80% have satellite leison
 Cavitation is uncomman
 Histoplasmosis
 Most frequent in lower lobe
 Well defined / seldom larger than 3cm
 Calcification common and central –target appearance
 Cavitation are rare

29.  HYADIT CYST
 Most common right lower lobe
 Common in endemic area
 Well defined , 1-10 cm in size
 Rupture result in –water lilly sign

30.  AVM:
Well defined and lobulated- Bag of worm appearence
dilated feeding arteries and draining vein may be visible
66% are single, calcification is rare
 Hematoma
peripheral ,smooth and well defined
slow resolution over several weeks
 Pulmonary infarction
Most frequent in lower lobe
wedge shaped area of consolidation can be identified abutting the
pleura , small u/l or b/l pleural effusion is seen

31. AVM WITH FEEDING
VESSELS

32.  Pulmonary sequestration
 usually more than 6cm in diameter
 2/3rd in left LL ,1/3rd in rt LL
 well defined round or oval lesion
 Confirmed by aortography and venous drainage is via
pulmonary vein or bronchial vein
 Bronchogenic cyst
 well defined, round or oval in shaped ,smooth wall
 2/3rd are intrapulmonary , located medial 1/3rd of LL
 Peak incidence in 2nd and 3rd decade of life

33.  standard CT examination without contrast
material enhancement may be performed
 Ensure there are no other findings, such as
additional nodules lymphadenopathy, pleural
effusion, chest wall involvement, or adrenal mass.
 concerns about radiation dose to the patient,
subsequent follow-up CT may be limited to the
nodule location.

34.  Thin-section CT scans obtained through the nodule
provide information regarding nodule size (by using
diameters from the largest cross-sectional area or volume
measurement) attenuation, edge characteristics, and the
presence of calcification,cavitation, or fat .
 Sequential thin-section CT (1 3-mm section width)
performed through the entire nodule with a single breath
hold and without contrast

35.  Absence of detectable growth over a 2-year period of
is a reliable criterion for establishing that a pulmonary
nodule is benign
 Difficult to detect growth in small (< 1cm) nodules. To
overcome this limitation,
 growth rate of small nodules be assessed using serial
volume measurements rather than diameter
 Computer-aided 3D quantitative volume measurement
methods have been developed and applied clinically
 All these volumetric methods are focused on solid
pulmonary nodule

36. Volume is doubled if diameter has increased by at least
1.25 times in at least 2 dimension
Usally malignant lesions have a doubling time of 1-6
months.
Masses are considered benign when they have not change
in size for 18 months
 many lesions are not completely spherical
 Hemorrhage into a lesion can increase the volume
dramatically
 bronchial carcinoids and BAC long doubling times

37.  The lesion should be at least 10mm
 Contrast enhancement is directly related to the
vascularity and blood flow
 Nodule examined 3mm collimation before and after
administration of contrast
 1min interval up to 4min after administration of contrast
 Nodule enhancement= peak mean – base line
attenuation

38.  Early cut of point for differention of benign from
malignant nodule - 15H enhancement
 Early study more focus on early phase of dynamic
CT .this studies are more sensitive but less specific
 Overlap was found between malignant and benign
nodules for example, active granulomas and benign
vascular tumours

39.  FALSE POSITIVE:
 active infection
 active inflammation
 FALSE NEGATIVE
 Broncho alveolar ca
 Lesion with central necrosis
 cavitatory lesion

40.  Special circumstances – contrast allergy etc
 Not routinely used due to cost factor
 CT is as good

41. TISSUE DIAGNOSIS
 TTNA-TRANS THORACIC NEEDLE
ASPIRATION
24 G needle
 CORE BIOPSY
 BRONCHOSCOPIC BIOPSY

42. indication
 FNAB can be used to diagnose malignancy and determine the
histologic type of malignancy. In patients who are candidates
for surgery
 FNAB may be used to diagnose benign disease, thus obviating
surgery
 Contraindications
 inability of the patient to cooperate
 Other relative contraindications
 bleeding diathesis,
 previous pneumonectomy, severe emphysema,
 severe hypoxemia,
 pulmonary artery hypertension,
 nodules which successful biopsy cannot be performed

43.  Nodules that are in the lower lobes or adjacent to the
heart may be difficult to access because of varying
breath holds and diaphragmatic and cardiac motion

44.  When the FNAB sample is interpreted as malignant or
specific benign condition is, further workup based on
diagnosis.
 when a nonspecific benign condition is diagnosed,
further evaluation is required
 The most common complications of
FNAB are pneumothorax and hemorrhage

45. PET with FDG-F18
 PET-CT may be selectively performed to characterize
SPNs when dynamic helical CT shows inconsistent results
between morphological and , hemodynamic characteristics
 PET 18F-FDG is accurate ,noninvasive diagnostic test
 PET-CT provide more anatomical detail than PET alone
or CT alone
 Increased uptake of 18F-FDG –MALIGNANT
 Decreased uptake - BENIGN
 False positive- infection /inflammation
 False negative –BAC, carcinoid
 Best test for lesion >1cm lesion

47. CLINICAL BENIGN MALIGNANT
Age < 35 yrs >35 yrs
h/o smoking - +
Exposure to
TB
+ -
Exposure to
carcinogens
- +
Primary
lesion
elsewhere
- +

48. Chest X ray BENIGN MALIGNANT
size < 3cm >3 cm
location Not specific Upper lobes
margins smooth Spiculated
calcification Central,
diffuse,
laminated,
popcorn
Eccentric/
stippled
Growth pattern Stable for 2 yrs Presence of
growth
Satellite nodule more less

49. CT BENIGN MALIGNANT
Fat + -
Bubble like
lucencies
uncommon Common
Enhancement < 25 HU > 25HU
densitometry > 200 HU < 200 HU

50.  ≥ 25 H wash-in and 5–31 H washout
 lobulated margin
 spiculated margin
 absence of a satellite nodule

51. NODULE SIZE
IN MM
LOW RISK PATIENT HIGH RISK PATIENTT
<4MM NO FOLLOWUP NEEDED IN ITIAL CT AT 12 MONTH,
IF UNCHANGED, NO
FOLLOWUP
4-6MM IN ITIAL CT AT 12 MONTH, IF
UNCHANGED, NO FOLLOWUP
INITIAL CT AT 6TO12
MONTH THEN AT 18 -24
MON IF NO CHANGE
6-8 MM INITIAL CT AT 6TO12 MONTH THEN
AT 18 -24 MON IF NO CHANGE
INITIAL CT AT 3 TO 6
MONTH THEN AT 9 TO 12
MON AND 24MON IF NO
CHANGE
>8MM CT FOLLOWUP 3, 9, 24
MON/DYNAMICCT/PET CT/BIOPSY
CT FOLLOWUP 3, 9, 24
MON/DYNAMICCT/PET
CT/BIOPSY
MacMahon, H. et al. Guidelines for management of small pulmonary nodules detected on CT scans:
A statement from the Fleischner Society. Radiology 2005; 237: 395-400
DO not use in pts <35y/o; h/o malignancy or in pts w fever.

52.  CT screening, has increased the detection rate of small
nodular lesions,
 In providing information about morphological and
hemodynamic characteristics with high specificity and
reasonably high accuracy,
 CT scan can be used for the initial assessment of SPNs.
 PET-CT is more sensitive for detecting malignancy than
dynamic helical CT, and all malignant nodules may be
potentially diagnosed as malignant by these two techniques.

53.  PET-CT may be selectively performed to
characterize SPNs when dynamic helical CT
shows inconsistent results between
morphological and hemodynamic characteristics
 Serial volume measurements are currently the
most reliable methods for the tissue
characterization of subcentimeteric nodule