SARCOIDOSIS

• Sarcoidosis is a systemic disorder of unknown cause characterized by the formation of non caseating granuloma.

• Pulmonary manifestations are present in 90% of patients, on bronchoscopy.

• 20%-25% of whom have permanent functional impairment.

• Pathologically, the most characteristic feature of sarcoidosis is the presence of noncaseating granulomas in a lymphatic or perilymphatic distribution.

There are four clinical stages of sarcoidosis based on the pattern of chest radiographic findings. 

• Stage I is defined as the presence of bilateral hilar lymphadenopathy only.

• Stage II is characterized by bilateral hilar lymphadenopathy and parenchymal disease.

• Stage III consists of parenchymal disease only.• Stage IV is characterized by pulmonary fibrosis.

• At presentation about 10% of patients will have no abnormal findings on chest radiography,

• 50% of patients will have stage I disease, • 25-30% will have stage II disease, • 10-15% will have stage III disease. • Patients rarely present with stage IV disease, but

approximately 20% of patients will eventually progress to this last stage. 

• CT of the chest is effective at demonstrating the extent of disease and may reveal subtle abnormalities not evident on chest radiographs. 

• The most characteristic HRCT abnormality in patients who have sarcoidosis consists of small nodules in a perilymphatic distribution, visible in relation to

• (i) the Peribronchovascular regions, adjacent to the perihilar vessels and bronchi

• (ii) the fissures, • (iii) the costal subpleural regions, • (iv) interlobular septa, and • (v) the centrilobular regions. 

• Nodules may coalesce into larger nodules and opacities. • Progression to pulmonary fibrosis may manifest as

reticular opacities, honeycombing, architectural distortion, traction bronchiectasis, and/or volume loss.

• Pulmonary findings of sarcoidosis are most common in the upper and mid-lung zones.

• HRCT demonstrates the characteristic symmetric hilar and paratracheal lymphadenopathy better than plain chest radiographs, despite the spacing of scans. 

• Lymph node calcification is not uncommon, and can be eggshell-like in appearance.

• These opacities shift towards the hila with progressive volume loss, architectural distortion, and fibrosis. 

• Cavitation and necrosis may develop within the central aspects of these opacities. 

Conditions that most closely mimic the HRCT appearance of sarcoidosis are

• pulmonary lymphangitic carcinomatosis (PLC), • Silicosis ,

• Berylliosis• Talcosis• Coal worker’s pneumoconiosis (CWP)

Alveolar sarcoidosis

• Alveolar sarcoidosis is a rare but distinct manifestation of pulmonary sarcoidosis, representing only 2%–10% of cases.

• The hallmark of alveolar sarcoidosis is airspace consolidation with air bronchograms, which changes rapidly.

• The airspace component of alveolar sarcoid generally resolves with or without treatment, although peribronchovascular sarcoid may persist thereafter.

• The main differential considerations include multifocal pneumonia, COP, bronchoalveolar carcinoma, MALT lymphoma, and alveolar proteinosis.

• The airspace component in alveolar sarcoid is thought to be caused by external compression and subsequent collapse of alveolar walls due to confluence of granulomas within the lung interstitium, rather than by actual infiltration of alveoli.

• Rarely these lesions can cavitate. The radiographic findings may appear abruptly and change rapidly.

• On thoracic CT, the galaxy sign may be seen, in which micronodules are evident at the periphery of the masses of alveolar sarcoidosis.

• The main differential considerations include • multifocal pneumonia, • bronchoalveolar carcinoma, • lymphoma, • alveolar proteinosis. 

2013 2013

2016

Alveolar Sarcoid/Lammellar sarcoid

2011-38 year old female

2013

Stage 1 to improvement

37 year old male in 2008

2015

Stage 1 progressed to Stage 3 sarcoid

50 year old female in -2014

CT no lung nodules

2016

Stage 1 stayed as stage 1.

61 Year old female

• Stage 4 Sarcoid• End stage• Pulmonary fibrosis• Egg shell calcification

47 year old female with headache in 2015

T1 Post T1 Post

2003

2015

• Pituitary Sarcoid• CXR Stage 1 has progressed to Stage 3 Sarcoid

T1 Cor, T2 FS,T1 Ax, Cor T1 FS

Cor, Axial post contrast and last non contrast

Stage 1

Stage 1

1999 Stage 1

2010-60 year old female

Stage 2

2015 Stage 4 almost

• Leptomemingeal neurosarcoid• Stage 2 lung sarcoid• Liver and spleen sarcoid

51 yr old male

Upper lobe bulla and miliary pattern

Stage 4 and Giant apical bulla from sarcoid42 yr old male

7 yrs prior

• The panda sign of sarcoidosis is a gallium-67 citrate scan finding. It is due to bilateral involvement of parotid and lacrimal glands in sarcoidosis, superimposed on the normal uptake in the nasopharyngeal mucosa.

• The presence of perihilar adenopathy adds the lambda distribution of increased uptake in the chest, which at times has been included in the description of the panda distribution.

• Garland triad, also known as the 1-2-3 sign or Pawnbrokers sign, is a lymph node enlargement pattern which has been described in sarcoidosis:

• right paratracheal nodes• right hilar nodes• left hilar nodes• Hilar lymphadenopathy is symmetrical and usually massive. These so-

called potato nodes don't usually abut the cardiac border which distinguishes it from lymphoma .

• Involvement of right paratracheal nodes reflects the ease with which these nodes are identified on plain radiography.

• Left paratracheal and aortopulmonary nodes are frequently enlarged but harder to identify . 

Cardiac Sarcoidosis

• Over half of patients with autopsy proven cardiac involvement are asymptomatic. Symptoms include :

• arrhythmias including sudden death (most common) and heart block

• congestive cardiac failure• angina pectoris (i.e. chest pain), palpitations and syncope• ventricular aneurysm formation• Although involvement of the pericardium is rare, 

constrictive pericarditis has been described 

• Cardiac manifestations of sarcoidosis are present in up to 25% of patients with sarcoidosis, but only 5-10% of patients are symptomatic.

• MRI• Modality of choice. Common MRI findings in patients with

cardiac sarcoid include:• delayed enhancement, which may be either mid-wall or transmural• nodular mid-wall hyperintense foci on black blood T2-weighted

imaging• areas of focal myocardial thickening

59 year old male

Delayed id myocardial enhancement and PH