++
For further information, see CMDT Part 9-22: Sarcoidosis
+++
Essentials of Diagnosis
++
Symptoms related to sarcoid involvement of
Lung
Skin
Eyes
Peripheral nerves
Liver
Kidney
Heart
Demonstration of noncaseating granulomas in biopsy specimen
Exclusion of other granulomatous disorders
+++
General Considerations
++
++
Highest incidence in North American Blacks and northern European Whites
Among Blacks, women are more frequently affected than men
Disease onset is usually in the third or fourth decade
++
Malaise, fever, and insidious dyspnea
Erythema nodosum, lupus pernio, iritis, peripheral neuropathy, arthritis, or cardiomyopathy
Parotid gland enlargement, hepatosplenomegaly, and lymphadenopathy
Some patients are asymptomatic, and diagnosis is made after abnormal findings are noted on chest radiograph
Physical findings of interstitial lung disease with crackles are uncommon
Myocardial sarcoidosis found in 5% of patients can lead to
+++
Differential Diagnosis
++
Other granulomatous diseases must be excluded
Tuberculosis
Histoplasmosis
Coccidioidomycosis
Lymphoma (including lymphocytic interstitial pneumonitis)
Idiopathic pulmonary fibrosis
Pneumoconiosis (especially berylliosis)
Syphilis
++
Leukopenia
Elevation of erythrocyte sedimentation rate
Hypercalcemia in 5%, hypercalciuria in 20%
Angiotensin-converting enzyme (ACE) levels
Elevated in 40–80% of patients with active disease
However, this finding is neither sensitive nor specific
Physiologic testing may reveal evidence of airflow obstruction and/or restriction with decreased lung volumes and diffusing capacity
ECG may show heart block and dysrhythmias
++
Radiographic findings are variable
Stage I: hilar adenopathy alone
Stage II: hilar adenopathy with parenchymal involvement
Stage III: parenchymal involvement alone
Stage IV: advanced fibrotic changes principally in the upper lobes
Parenchymal involvement usually manifests as diffuse reticular infiltrates, but focal infiltrates, acinar shadows, nodules, and rare cavitation may be seen
Pleural effusion occurs in < 10% of patients
Cardiac magnetic resonance imaging (MRI) is favored over positron emission tomography (PET) scan for patients with suspected cardiac involvement
+++
Diagnostic Procedures
++
Biopsy demonstrating noncaseating granulomas is required for diagnosis
Easily accessible biopsy sites include lymph nodes, skin lesions, and salivary glands
Transbronchial biopsy has a yield of 75–90%
Some experts believe biopsy is unnecessary in stage I disease with a presentation highly suggestive of sarcoidosis
Bronchoalveolar lavage is usually characterized by an increase in lymphocytes with a high CD4/CD8 cell ratio, but it does not establish a diagnosis
Assessment for pulmonary hypertension is recommended in advanced disease
++