3. Sarcoidosis is a disease with highly variable manifestations, ranging from
asymptomatic to progressive, relapsing disease.
Typically sudden onset with spontaneous remission in approximately two-
thirds of patients [3]
Approx. one-third of patients develop progressive chronic disease.
Most common presenting signs and symptoms
General: fever, malaise
, lack of appetite, weight loss, lymphadenopathy.
Pulmonary: dyspne , cough, chest pain
Extrapulmonary: arthriti,s erythema nodosum
, anterior uveitis
4.
5.
6.
7. Sarcoidosis is a diagnosis of exclusion supported by:
Characteristic clinical features and/or findings on chest imaging
Noncaseating granulomas on biopsy
Exclusion of more common causes of granulomatous disease
or lymphadenopathy
Laboratory studies
CBC and differential: leukocytopenia
Inflammatory markers
: ↑ ESR CRP
Hypercalcemia
↑ BUN , creatinine
: may indicate tubulointerstitial disease
↑ ALP and/or GGt may indicate hepatic involvement
[7]
12-lead ECG
: concerning findings include heart block frequent PVCs, tachyarrhythmias
10. Since Ga-67 citrate accumulates in areas of inflammation and malignancy, the differential diagnosis for the
symmetric bilateral accumulation in the lacrimal and salivary glands include lymphoma (after
irradiation), Sjögren syndrome and acquired immunodeficiency syndrome
16. ▶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.
17. ▶Uncommon findings:
Conglomerate masses in a perihilar location.
Larger nodules (> 1cm in diameter, in Grouped nodules or coalescent nodlues
surrounded by multiple satellite nodules (Galaxy sign)
Nodules so small and dense that they appear as ground glass or even as
consolidations (alveolar sarcoidosis)
18. Nodules with a typical perilymphatic distribution. Scheme of distribution (A) MIP axial planes (B) and
MIP coronal planes (C) showing perilymphatic nodules in sarcoidosis with typical involvement of dorsal
regions of upper lobes.
19. A typical presentation of sarcoidosis with hilar lymphadenopathy and small nodules along bronchovascular
bundles (yellow arrow) and along fissures (red arrows)
20. nodules along bronchovascular bundle (red arrow) and fissures (yellow arrow).
This is the typical perilymphatic distribution of the noduless.
21. Typical manifestations of pulmonary sarcoidosis. (a) Axial high-resolution CT scan shows multiple micronodules with a
peribronchovascular distribution in both lungs, predominantly in the upper and middle lobes. One cluster of nodules in the
periphery of the left upper lobe (arrow) has coalesced to form a conglomerate lesion (macronodule). (b) Coronal reformatted
image from high-resolution CT clearly shows upper-lobe predominance of the micronodules.
22. ▶ Progressive fibrosis in sarcoidosis may lead to peribronchovascular (perihilar)
conglomerate masses of fibrous tissue.
▶ The typical location is posteriorly in the upper lobes, leading to volume loss of
the upper lobes with displacement of the interlobar fissure.
▶
24. HRCT scans at the level of the aortic arch (A) and the pulmonary trunk (B) showing a classic appearance of advanced fibrotic
sarcoidosis. A dense conglomerate mass in the right upper lobe and bilateral traction bronchiectasis that radiate from the hilum
towards the dorsal regions of upper lobes. There is also evident intralobular interstitial thickening in the upper lobes.
25. Small satellite nodules are often identified at the periphery of these masses,
giving an appearance that has been termed the "sarcoid galaxy sign".
26. Axial high-resolution CT scan shows several large, ill-defend nodules and areas of consolidation resulting from the confluence of multiple parenchymal
micronodules composed of numerous tiny granulomas in both lungs. Fine nodular opacities are seen around the large nodules , and small low-attenuation
spots that correspond to the spaces between partially coalescent small nodules are visible peripherally. This appearance has been termed the sarcoid galaxy
sign.
27. Alveolar sarcoid pattern of airspace consolidation in pulmonary sarcoidosis. Axial high-resolution CT scan shows alveolar consolidation in the
left upper lobe and patchy subpleural alveolar opacities in the right
upper lobe. Architectural distortion and traction bronchiectasis, signs of fibrosis, also are evident
28. AIRWAY INVOLVEMENT The most common imaging findings of airway
involvement are a mosaic attenuation pattern, air trapping, tracheobronchial
abnormalities and atelectasis.
Mosaic Attenuation Pattern: It refers to the presence of heterogeneous attenuation
in the lung parenchyma on inspiratory CT images. In patients with sarcoidosis, this
pattern results from airway involvement by granulomas or fibrosis, which may lead
to obstruction.
29. Axial unenhanced high-resolution expiratory CT scan obtained in a patient with pulmonary sarcoidosis shows a mosaic pattern
consisting of multiple areas of low attenuation , interspersed with larger areas of normal lung parenchyma. This appearance is
produced by air trapping.
30.
31. Pleural involvement in sarcoidosis is demonstrated. Axial CT scan shows bilateral hilar and subcarinal
lymphadenopathy, indicating sarcoidosis. Right pleural effusion is present. Note pleural thickening
(arrow). Pleural biopsy revealed presence of sarcoidosis.
32. Stage IV pulmonary sarcoidosis in a 62-year-old man. Thoracic CT demonstrates extensive fibrotic change with a central distribution that
distort the lung parenchyma and a cavitary lesion, predisposing to fungal infection, an aspergiloma (arrows). Note the presence of lymph
nodes calcifications and the enlargement of pulmonary artery, a finding that suggests pulmonary hypertension
DILATED PUL.TRUNK>29mm
Ratio of main pul artery to
ascending aorta>1
33. ▶ Lymphadenopathy:
1. Primary TB: asymmetrical adenopathy
2. Histoplasmosis
3. Lymphoma
4. Small cell lung cancer with nodal metastases
▶ Nodular pattern:
1. Silicosis / Pneumoconiosis: predominantly centrilobular and subpleural nodules.
2. Miliary TB: random nodules.
38. CARDIAC SARCOIDOSIS
Cardiac sarcoidosis can result in various cardiac abnormalities including atrioventricular
block,bundle branch block, ventricular tachycardia,heart failure, and sudden death
The criterion standard for diagnosis of cardiac sarcoidosis is histologic confirmation of
noncaseating granulomas by means of endomyocardial biopsy
CARDIAC MRI
There is no specific pattern of late gadolinium enhancement at cardiac MR imaging
that is diagnostic for cardiac sarcoidosis. However, cardiac sarcoidosis usually is associated with
patchy and multifocal late gadolinium enhancement, and tends to affect the mid myocardium
and epicardium, sparing the subendocardium.
FDG PET
Active sarcoidosis is associated with patchy focal 18F FDG uptake .
Presence of focal 18F FDG uptake with or without a perfusion defect suggests active
inflammatory sarcoidosis.
39.
40. Late gadolinium enhancement (LGE) patterns.
LGE allows differentiation between different
pathological substrates, based on the different
scar distribution: subendocardial (a) and
transmural (b) patterns indicate an ischemic
cardiomyopathy; patchy (c) and mid-wall (d)
distribution indicate a nonischemic
cardiomyopathy (such as dilated and
hypertrophic cardiomyopathy); a subepicardial
pattern (e) is typically post-inflammatory (such
as myocarditis); a diffuse subendocardial
pattern (f) is typical of amyloidosis or, in rarer
situations where LGE is thinner and less diffuse,
of endomyocardial fibrosis.
41. Cardiac sarcoidosis : A short-axis image of delayed-enhanced MRI reveals severe extent of hyper enhancement in septal, inferior,
and anterolateral regions (white arrows). B and C, Cine MRI obtained at end diastole (B) and end systole (C) in a basal short-axis
slice show wall motion abnormalities in septal and inferior walls (black arrows). Also see Movie I. D, A short-axis image of
201thallium single photon emission tomography demonstrates perfusion defects in septal and
inferior regions (white arrows), where severe extent of enhancement is seen in a delayed enhanced MR image. E, A short-axis image
of fasting FDG PET shows FDG accumulation in septal, inferior, and anterolateral walls (white arrows), corresponding to areas with
late enhancement.
42. NEUROSARCOIDOSIS
Neurosarcoidosis in a 53-year-old woman.
(a) Coronal contrast material–enhanced T1-weighted
MR image shows thick nodular pachymeningeal enhancement
(arrows) along the basilar dura, including
near the cerebellopontine angles and tentorial
reflections bilaterally. (b) Axial contrast-enhanced
T1-weighted MR image shows nodular enhancement
along the seventh and eighth cranial nerve complex (arrow).
(c) Axial T2-weighted fluid-attenuated inversionrecovery
MR image shows a hyperintense lesion in the
left medulla (arrow), a finding consistent with intraparenchymal
involvement.
43. Neurosarcoidosis in a 67-year-old woman. Axial contrast-enhanced T1-weighted MR image
shows nodular enhancement in the left optic nerve (arrow), sella turcica, and leptomeningeal region. (8) Pituitary
sarcoidosis in a 32-year-old woman. Sagittal contrast-enhanced T1-weighted MR image shows an avidly
and heterogeneously enhancing nodular mass in the sella turcica, extending to the optic chiasm
44. Osseous sarcoidosis in a 43-year-old man.
Radiograph of the left hand shows lace-like
osteolysis in the phalanges, withmultiple well-
defined lytic lesions (arrows). Note the
preservationof joint space and the absence of
periosteal reaction.
Musculoskeletal Sarcoidosis
Sarcoidosis can involve the bones, joints, and
muscles.
Small bones of the hand (in particular, the distal and middle
phalanges of the second and third digits) are
involved more commonly .
Soft-tissue thickening may be seen surrounding the fingers
and is referred to as “sausage dactylitis.”
At radiography, a lace-like pattern of osteolysis
with thickened trabeculae and a thin cortex are
characteristically seen in the small bones of the
hands and feet. A periosteal reaction is
typically absent.
45. US
may show hepatomegaly, heterogeneous liver Parenchyma and may reveal
innumerable small hypoechoic lesions in 5%–19% of patients .
CT : hypoidense nodules, which typically measure only a few millimeters, but
larger lesions may develop, especially when the smaller lesions coalesce .
MRI: These sarcoidosis nodules are usually hypointense on both T1- and T2-
weighted MR
images
The differential diagnosis includes evaluation for metastases, lymphoma,
fungal microabscesses,
and mycobacterial infections.
Whenthere is doubt regarding the definitive diagnosis,biopsy may be
warranted.
ABDOMINAL SARCOIDOSIS
46. Hepatic sarcoidosis in a 50-year-old man. US image shows numerous small poorly defined
hypoechoic lesions (arrows). A diagnosis of hepatic sarcoidosis was confirmed on the basis of biopsy results. Small
hepatic sarcoid lesions may be difficult to evaluate with US but are often better visualized with CT and MR imaging.
(13) Hepatosplenic sarcoidosis in a 33-year-old man. Axial CT image of the abdomen shows many tiny hypointense
nodules in the liver (white arrows), slightly larger hypointense nodules in the spleen (arrowhead), and multiple
upper
abdominal nodes (black arrow).
47. Splenic sarcoidosis in a 38-year-old woman.
(a) US image shows many small hypointense lesions in
the
spleen (arrows). (b) Axial contrast-enhanced T1-
weighted
MR image shows small hypovascular lesions in the
spleen
(white arrows) and liver (black arrows). (c) Axial
diffusionweighted
image with a high b value (800 sec/mm2) shows
many tiny lesions in the spleen (white arrows) and liver
(black arrows) with restricted diffusion
48.
49. Silicosis
⚫principal sources- free silica in mining, quarrying, and tunneling.
⚫fine crystalline silicon dioxide Inhalation
⚫Silica particles- breakdown of macrophage releases enzymes –
progressive fibrogenic response even after cessation of
dust exposure.
50. Silicosis
⚫small, well-circumscribed nodules that are 2–5 mm in dia, mainly
inv upper & posterior lung zones.
GGO
⚫20% calcify centrally
⚫Lymphadenopathy is common
⚫Eggshell calcification of hilar nodes (5%) DDx: Sarcoidosis
55. CHRONIC SIMPLE SILICOSIS
⚫10--20 years of dust exposure
⚫Rt upper lobes--posterior lung zones
⚫nodules are in perilymphatic distribution
⚫centered along the bronchovascular bundles, centriacinar
portion of the lobule, & in the subpleural lung,
where the nodules form these pseudoplaques.
56. ⚫1-10mm well defined rounded opacities
centrilobular & peribronchial;
⚫nodules surrounded by focal emphysema (focal dust emphysema)
⚫calcify
⚫hilar + mediastinal lymphadenopathy, may calcify in 5% (eggshell pattern)
58. COMPLICATED SILICOSIS(PROGRESSIVE
MASSIVE FIBROSIS)
Large opacities >1cm diameter
Mid zone/ periphery of upper lung migrating towards hila
Relatively b/l symmetrical and non segmental
Conglomerated sausage shape with ill defined margins
Compensatory emphysema in unaffected portion
between mass and pleura
May cavitate and calcify
59.
60. CXR-large b/l opacities in the upper zones of the lung, as well as upward elevation of both hila.
CT-shows bilateral conglomerate masses with calcifications, findings that
represent PMF in the upper zone of both lungs.
