Sarcoidosis is a systemic granulomatous disease of unknown origin characterized by non-caseating granulomas that commonly affect the lungs. Pulmonary manifestations are present in 90% of patients and include bilateral hilar lymphadenopathy and pulmonary infiltrates. While two thirds of patients experience remission within ten years, one third have progressive disease that can lead to pulmonary fibrosis and, in rare cases, death. Computed tomography is more sensitive than chest x-rays in detecting lymph node enlargement and lung abnormalities associated with sarcoidosis.

2.  Sarcoidosis is a systemic disorder of unknown
origin.
 It is characterized by non-caseating
granulomas in multiple organs, that may
resolve spontaneously or progress to fibrosis.
 Pulmonary manifestations are present in 90%
of patients.

3.  Systemic symptoms such as fatigue, night
sweats and weight loss are common.
 Löfgren's syndrome, an acute presentation of
sarcoidosis, consists of arthritis, erythema
nodosum, bilateral hilar adenopathy.

4.  Two third of patients have a remission within
ten years.
 One third have continuing disease leading to
clinically significant organ impairment.
 Less than 5% of patients die from sarcoidosis
usually as a result of pulmonary fibrosis.

5. Radiographic staging of
Sarcoidosis
 Stage O is a normal chest radiograph
 Stage I BHL without pulmonary infiltrates
 Stage II BHL with pulmonary infiltrates
 Stage III Pulmonary infiltrates without BHL
 Stage IV Extensive pulmonary fibrosis

6. A PA view of the chest demonstrates right paratracheal (red
arrow) and bilateral hilar (white arrows) lymphadenopathy

7. The CT scan confirms bilateral hilar lymphadenopathy (arrows. The lung
parenchyma was normal. Differential diagnosis included primary and
secondary neoplasms and granulomatous disease

8. Stage???
Stage I disease

9. Stage???
Stage II disease

10. Pulmonary window CT shows small nodules mostly along the
bronchovascular bundles, giving the bronchi and vessels a
beaded appearance

11. Stage???
Stage III

12. Stage???
Stage I

13. Stage???
Stage II

14. Stage???
Stage 0 radiographic sarcoidosis. This normal chest x-ray
may be observed in 5 to 15% of cases

15. Stage???
stage IV

16. Stage???
Stage IV

17. Stage???
Stage IV

18. Conventional chest radiographs
 Over 90% of patients with sarcoidosis manifest
abnormalities on chest radiographs
 Commonest feature-BHL (50-80%)
 Concomitant enlargement of right paratracheal
lymph nodes is common
 Pulmonary parenchymal infiltrates (25 to 50%)

19.  Parenchymal infiltrates are often symmetrical
and bilateral, with a predilection for the
central (rather than peripheral) regions and
upper lobes (particularly posterior and apical
segments)
 Reticular, reticulonodular, or focal alveolar
opacities are most characteristic

20.  Destruction of lung parenchyma may lead to
-architectural distortion
-hilar retraction
-upper-lobe volume loss
-broad and coarse septal bands
-honeycomb change
-large bullae

21.  With advanced stage III or IV sarcoidosis,
enlarged pulmonary arteries (attributable to
secondary pulmonary arterial hypertension)
and bronchiectasis may be observed.

22. Reticular opacities

23. Reticulonodular opacities

24. Focal alveolar opacities

25. Posteroanterior chest radiograph demonstrates extensive
ground-glass, miliary infiltrates throughout both lung fields

26. Posteroanterior chest radiograph reveals multiple dense alveolar
nodular. Bilateral hilar lymphadenopathy is also present

27. Unusual chest radiographic
features
The prevalence of atypical features is higher in
sarcoid patients presenting after the age of 50
 Pleural effusion
 Pleural thickening
 Pneumothorax
 Cavitation
 Bronchostenosis
 Vascular involvement (pulmonary vessels)
 Unilateral hilar lymphadenopathy

28. Computed tomographic scanning
in Sarcoidosis
 INDICATIONS
(a) atypical clinical and/or chest radiographic
findings.
(b) detection of complications of the lung
disease.
(c) a normal chest radiograph but a clinical
suspicion for sarcoidosis.

29.  CT scan provide improved anatomic lung
detail and are more sensitive than plain chest
radiographs in delineating parenchymal,
mediastinal, and hilar structures.
 CT scan may detect enlarged lymph nodes or
parenchymal infiltrates that are below the
resolution of conventional chest radiographs

30.  Enlarged lymph nodes are often observed in
paratracheal, pretracheal, para-aortic, internal
mammary, subcarinal, or axillary regions,
which are not appreciated on chest
radiographs.
 Calcified hilar or mediastinal lymph nodes may
be observed in patients with longstanding
sarcoidosis

31.  Calcified lymph nodes may also be observed
in tuberculosis, silicosis, and other chronic
granulomatous disorders.
 The lymph nodes in sarcoidosis are larger
than those in tuberculosis, more often focal,
and less likely to be completely calcified

32.  Lymph node calcification is bilateral in most
of patients with sarcoidosis, but usually
unilateral in most of patients with
tuberculosis

33. para-aortic lymph node enlargement

34. Bilateral hilar lymphadenopathy and marked widening of
the carina due to enlarged subcarinal lymph nodes (arrow)

35. HRCT findings in
sarcoidosis
 Common findings:
 Small nodules in a perilymphatic distribution (i.e.
along subpleural surface and fissures, along
interlobular septa and the peribronchovascular
bundle).
 Upper and middle zone predominance.
 Lymphadenopathy in left hilus, right hilus and
paratracheal .Often with calcifications

36.  Uncommon findings:
 Conglomerate masses in a perihilar location.
 Larger nodules (> 1cm in diameter, in < 20%)
 Grouped nodules or coalescent nodlues
surrounded by multiple satellite nodules (Galaxi
sign)
 Nodules so small and dense that they appear as
ground glass or even as consolidations (alveolar
sarcoidosis)

37. small nodules along bronchovascular bundles (yellow
arrow) and along fissures (red arrows)

38. small nodules in a perilymphatic distribution along
bronchovascular bundles and along fissures (yellow arrows)

39. conglomerate masses of fibrous tissue

40. Sarcoidosis with fibrosis in the upper lobes

41. alveolar sarcoidosis

42. fibrosing sarcoidosis

43. Differential diagnosis of
sarcoidosis
 Lymphadenopathy:
Primary TB: asymmetrical adenopathy
Histoplasmosis
Lymphoma
Small cell lung cancer with nodal metastases
 Nodular pattern:
Silicosis / Pneumoconiosis: predominantly
centrilobular and subpleural nodules.
Miliary TB: random nodules

44.  Fibrotic pattern:
Usual Interstitial Pneumonia (UIP): basal and
peripheral fibrosis, honeycombing.
Chronic Hypersensitivity Pneumonitis: mid zone
fibrosis with mosaic pattern.
Tuberculosis (more unilateral).