| What is sarcoidosis? | Chronic multisystem disorder of unknown origin
Non-caseating granulomatous accumulation of T lymphocytes and macrophages leading to dearangement of architecture.
Usually affects lungs and intrathoracic lymph nodes (90%), also skin and eye (20-30%) and other organs (spleen, CNS..., 2-7%) |
| How is the clinical expression of sarcoidosis? | Very heterogenous.
50% asymptomatic with incidental bilateral hilar adenopathy, symptoms vary according to organ involved
spontaneous remission in 25-50% of cases.
Usually associated with erythema nodosum, polyarthritis, fever (Lofgren syndrome) --> excellent prognosis with high rate of spontaneous remission
When it affects black race, has bone involvement, ass with lupus pernio (nasolabial cutaneous lesion), hypercalcemia and chronic pulmonary sarcoidosis it is bad prognosis.
MR at 5 years =7% / 4% |
| What is the etiology of sarcoidosis? | Unknown cause, infectious and non-infectious causes related, exaggerated immune response to antigens |
| How is the pathology of sarcoidosis? | Hallmark (non-caseating granuloma)
May be mistaken with mycobacterial and fungal infection, so it is tested using special stain for fungi and acid fast bacilli to exclude them
Usually multinucleated giant cell surrounded by lymphocytes and mononuclear cells
In lungs situated in submucosa of bronchioles, and in bronchovascular bundles.
It may lead to organ destruction, significant loss of function, and end-stage fibrosis (honeycomb lung) |
| What are labs done for sarcoidosis? | Non-specific
Hypercalcemia and hypercalciuria (increased 1,2-dihydroxycalciferol by granuloma)
ACE serum elevated (30-80%) but not specific for sarcoidosis |
| What are the imaging findings in sarcoidosis? | Bilateral hilar and right paratracheal adenopathies (classic in 2/3 of pt - stage I sarcoidosis)
Cystic radiolucencies (honeycombing) and fibrosis with predilection of upper lobe of both lungs + Bilateral hilar lymphadenopathy + linear fibrosis and volume loss + lung infiltrates (stage II sarcoidosis) [ rare cavitations and pleural effusions]
With advaced disease, mycetomas bullous emphysema and pulmonary HTN and calcification of adenopathies (stage IV) |
| What are the radiologic stagings of sarcoidosis? | Stage 0 ->normal
Stage I -> BHL without infiltrates
Stage II -> BHL with infiltrate
Stage III ->Infiltrate without intrathoracic adenopathies
Stage IV -> Extensive detruction, fibrosis and volume loss
Useful for prognosis (remission 60-90% stage I, 40-70% stage II and 10-20% stage III spontaneous)
within first 6 months remission |
| What is the use of CT scan in sarcoidosis? | Chest CT more sensitive then CXR, sees delineating parenchymal details and adenopathies, thin slice HRCT even better discriminating alveolitis from fibrosis.
Nodules (80% are aggregates of granulomas)
Cardinal sign: thickening of bronchovascular bundles with beaded appearance, ground glass opacity (16-84%)
may form conglomerate masses, shape distortion and cystic destruction, and cavitation in 2.7% of advanced disease
We can see bronchial thickening, consolidations, large cystic bolus change and distortion of architecture in advanced disease |
| What is the result of PFT in sarcoidosis? | Restrictive physiology (30-60%), airway obstruction with reduced FEV1 and expiratory flow rates 9-40% reflect endobronchial inflammation and parenchymal distortion.
DLCO more sensitive but less degree of impairment than IPF
PFTs are done serially as assessment of therapy |
| How is the pathological diagnosis of sarcoidosis? | Bronchoscopy with TBBx
several biopsies of lobes (95% dx)
TBNA and mediastinoscopy shows granuloma when TBBx not effective
Surgical biopsy is needed |
| What are the extrapulmonary manifestations of sarcoidosis? | Adenopathies (intrathoracic nodules 75%, peripheral adenopathy also common, no ulceration, non tender and firm)
Eye (25% may lead to blindness, anterior uveitis (most pt) or posterior uveitis (less common), blurred vision, tearing and photophobia, maybe conjuctiva involvement)
Skin (25%, plaques, maculopapular rash, subcutaneous nodules, lupus pernio (blue purple lesions in nose cheeks knees ears and fingers, may go to bone), erythema nodosum (not specific seen in arthralgia)
Upper RT (nasal mucosa 20%, mouth, larynx 5% ->hoarseness, stridor and complete obstruction)
Bone marrow and spleen (15-40% rarely hemato)
Liver (>60%, liver function disorder, hepatomegaly 20% with mild cholestatic pattern)
Kidney (Hypercalciuria, nephrocalcinosis, nephrolithiasis, rarely clinically apparent)
NS (5% cranial nerves, facial palsy, optic nerve involved, hearing abnormality, meningitis, neuropathies peripheral and psych)
Musculoskeletal (Joint involved 25-50%, arthralgia and arthritis and bone lesions 5%)
Heart (5%, LV dysfunction, arrhythmias sometimes heart blocks pericarditis and cor pulmonale)
Endocrine (hypopituitarism rare, DI common, cystic lesions can be tender)
Exocrine (parotid enlargement common apparent 10%)
GI (autopsy rarely clinically apparent) |
| What is the treatment of sarcoidosis? | Corticosteroids (dramatic remissions are possible in 60-90%)
Relapse may occur 16-74% of cases, but we may have spontaneous remission
Usually we use immunosupressive Rx (methotrexate, cyclosporin) and not inhaled corticosteroids.
NSAIDs effective for joints involvement but not severe pulmo and extrapulmo
Antimalarial drugs (chloroquine) immunomodulating effect in granuloma (in cutaneous, osseous, neuro sarcoidosis and hypercalcemia), but since chloro is ocular toxic, it is preferred to use hydroxychloroquine (200mg once/twice a day for 6-months
Long term maintainance of Rx is needed (100-400 mg/day) + slit-lamp exam for ocular toxicity monitoring |
| What are the medications used in sarcoidosis tx? | Infliximab and thalidomide (refractory sarcoidosis (cutaneous disease))
Infliximab (systemic sarcoidosis - lupus pernio, hepatic, neurosarcoidosis)
Tetracyclines (cutaneous sarcoidosis) |
| How do we assess prognosis of sarcoidosis? | Many don't need tx, spontaneous remission
Poor prognosis (advanced CXR stage, extrapulmonary involvement (neuro or cardio), pulmonary HTN. |
