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
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.
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
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)
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).
Editor's Notes
Sarcoidosis, thoracic. Stage I disease. Standard posteroanterior chest radiograph in a 28-year-old man shows extensive bilateral hilar and mediastinal lymph node enlargement not associated with a pulmonary abnormality
Sarcoidosis, thoracic. Stage II disease. Chest radiograph in a 36-year-old woman shows mediastinal lymph node enlargement and bilateral pulmonary opacities.
Sarcoidosis, thoracic. Pulmonary window CT image in the same patient as in the previous image shows small nodules mostly along the bronchovascular bundles, giving the bronchi and vessels a beaded appearance. This distribution along the bronchovascular bundles accounts for the fact that transbronchial biopsy is usually successful for obtaining tissue for diagnosis.
Sarcoidosis, thoracic.Stage III Posteroanterior (PA) chest radiograph in a 38-year-old man shows stage III disease associated with a tumefactive type of lung parenchymal involvement: opacities in the right and left mid lung zones that mimic neoplasm.
Stage I sarcoidosis. Posteroanterior chest radiograph demonstrates bilateral hilar and right paratracheal lymphadenopathy. Lung fields are clear.
Stage II sarcoidosis. Posteroanterior chest radiograph demonstrates massive bilateral hilar lymphadenopathy as well as bilateral parenchymal infiltrates. Note the predilection for mid and upper lung zones.
Stage 0 radiographic sarcoidosis. This normal chest x-ray may be observed in 5 to 15% of cases
typical chest film of long standing sarcoidosis (stage IV) with fibrosis in the upper zones and volume loss of the upper lobes resulting in hilar elevation. Fibrosis results in obliteration of pulmonary vessels, which can lead to pulmonary hypertension.
Stage IV pulmonary sarcoidosis in a 48-year-old man. (a) Chest CT scan (lung window) demonstrates traction bronchiectasis (arrowheads) and fibrotic lesions with extensive calcification, findings that indicate stage IV disease. (b) Chest CT scan (mediastinal window) demonstrates calcification in the fibrotic lesions, mediastinal adenopathy, and irregularly thickened pleura (arrowheads).
Stage IV pulmonary sarcoidosis in a 60-year-old man. Chest CT scan demonstrates extensive fibrotic change and cavitary lesions with a central distribution (arrows) that distort the lung parenchyma. Irregular thickening of the pleura (arrowheads) and overinflation of the peripheral lung parenchyma are also seen.
Diffuse miliary or ground-glass patterns are exceptionally rare
Confluent alveolar opacities with consolidation or multiple well-circumscribed pulmonary nodules are less common features of sarcoidosis
Reticular opacities
Reticulonodular opacities
Focal alveolar opacities
Sarcoidosis. Posteroanterior chest radiograph demonstrates extensive ground-glass, miliary infiltrates throughout both lung fields in a 22-year-old black female with a 4-month history of dyspnea. Transbronchial lung biopsies demonstrated confluent, noncaseating granuloma. Special stains and cultures for acid-fast bacilli and fungi were negative. Corticosteroids (prednisone 40 mg/day) led to dramatic improvement.
(A) Nodular sarcoidosis. Posteroanterior chest radiograph reveals multiple dense alveolar nodular infiltrates in a 36-year-old woman. Bilateral hilar lymphadenopathy is also present. Transbronchial lung biopsies demonstrated confluent noncaseating granulomas consistent with sarcoidosis. The infiltrates resolved following institution of corticosteroid therapy.
Chest computed tomographic (CT) scan from a patient with stage I sarcoidosis at the level of the carina shows extensive para-aortic lymph node enlargement (arrows).
Chest CT scan from the same patient following intravenous contrast. Bilateral hilar lymphadenopathy and marked widening of the carina due to enlarged subcarinal lymph nodes (arrow) are present
a typical presentation of sarcoidosis with hilar lymphadenopathy and small nodules along bronchovascular bundles (yellow arrow) and along fissures (red arrows).
typical presentation of sarcoidosis with mediastinal lymphadenopathy and small nodules in a perilymphatic distribution along bronchovascular bundles and along fissures (yellow arrows).Always look for small nodules along the fissures, because this is a very specific and typical sign of sarcoidosis.
Sarcoidosis with conglomerate masses of fibrous tissue
Sarcoidosis with fibrosis in the upper lobes. Typical HRCT findings.
stage IV sarcoidosis.; Notice the distribution of the conglomerate masses of fibrosis in the posterior part of the lungs. In addition there are multiple small well-defined nodules. Some of these nodules have the typical sub pleural distribution.
a case of alveolar sarcoidosis. In this case the appearance resembles a ground glass attenuation, but with a close look you may appreciate that the increased attenuation is the result of many tiny grouped nodules. Also notice the hilar lymphadenopathy.
a case of fibrosing sarcoidosis, showing fibrosis, traction bronchiectases and crowding of the involved bronchi, predominantly in the perihilar region and upper lobes. Nodular abnormalities are absent, but the appearance and the location of the fibrosis are very suggestive of the diagnosis of sarcoidosis.