Diagnosis
Definite diagnosis becomes increasingly difficult, the more severe the disease becomes, because the granuloma characteristics disappear.
1. Chest X ray
2. Lung Function Tests would be likely to show a restrictive lung deficit even in the absence of fibrosis.
- Biopsy.
- Transbronchial lung is the most diagnostically informative investigation.
- Bronchoalveolar lavage (“washout” of bronchial tree, to demonstrate cells) which produces fluid containing an increased proportion of lymphocytes.
- Mediastinoscopy and video- assisted thorascopy (direct visualisation)
- Gallium scan (radionuclide scanning procedure) which demonstrates an abnormal uptake in affected organs.
- High-resolution CT scanning can show up lymph nodes. Non-contrast CT can define extent and pattern of lung tissue involvement.
- Serum ACE (Angiotensin-Converting Enzyme) level. This is often raised in Sarcoidosis, especially in acute disease.
- Serum biochemistry: Serum calcium is raised in 10% of cases. There is also raised gammaglobulin in the blood. There may be a raised serum alkaline phosphatase (liver function test).
- Full blood count: There may be mild reductions in lymphocytes and neutrophils. The erythrocyte sedimentation rate (ESR) may be raised.
- A strongly positive test would exclude sarcoidosis.
- Tuberculosis
- Streptococcal infection
- Ulcerative colitis
- Crohn’s Disease
- Some prescribed drugs such as oral contraceptives, aspirin, and sulphonamides
3. Blood Tests
4. Tuberculin Test
Differential Diagnosis
The main diagnoses to be excluded are:
1. Pulmonary tuberculosis (although it is rare in this condition for the hilar lymph nodes to be symmetrically enlarged).
2. Lymphoma (it is rare for only the hilar lymph nodes to be symmetrically affected in lymphoma).
3. Carcinoma of the bronchus with lymph node spread (it, again, is rare for just the hilar lymph nodes to be affected, and if so, the involvement tends to be unilateral). Chronic Beryllium Disease (the outcome of immunological sensitisation to the element beryllium) – despite stricter restrictions, low levels of exposure can cause sensitisation that may progress to chronic beryllium disease in some individuals). An example of exposure is working in the nuclear industry in the UK.
4. Erythema Nodosum is also associated with:
Amended November 2008
