Diagnosis Preliminary diagnosis of sarcoidosis is based on the patient's medical history, routine tests, a physical examination, and a chest x-ray.
The doctor confirms the diagnosis of sarcoidosis by eliminating other diseases with similar features. There include such granulomatous diseases as berylliosis, tuberculosis, farmer's lung disease (hypersensitivity pneumonitis), fungal infections, rheumatoid arthritis, rheumatic fever, and cancer of the lymph nodes (lymphoma).
Medical signs and symptoms
In addition to the lungs and lymph nodes, the body organs more likely than others to be affected by sarcoidosis are the liver, skin, heart, nervous system, and kidneys, in that order of frequency. Rarely, any organ can be involved. Patients can have symptoms related to the specific organ affected, they can have general symptoms, or they can be without any symptoms. Symptoms can vary according to how long the illness has been present, where the granulomas are forming, how much tissue has been involved and whether the granulomatous fibrotic process is active.
Even when there are no symptoms, a doctor can sometimes pick up signs of sarcoidosis during a routine examination, usually a chest x-ray. The patient's age and race or ethnic group can raise an additional red flag that a sign or symptom of illness could be related to sarcoidosis. Enlargement of the salivary or tear glands and cysts in bone tissue are also possible signs of sarcoidosis.
LUNGS: The lungs are usually the first site involves in sarcoidosis. Indeed, about 9 out of 10 sarcoidosis patients have some type of lung of problem, with nearly one-third of these patients showing some respiratory symptom usually coughing, either dry or with phlegm, and dyspnea (shortness of breath). Occasionally, patients have chest pain and a feeling of tightness in the chest. It is thought that sarcoidosis of the lungs begins with alveolitis (inflammation of the alveoli), the tiny sac like air spaces in the lungs where carbon dioxide and oxygen are exchanged. Alveolitis either clears up spontaneously or leads to granuloma formation. Eventually fibrosis (scarring) can form, causing the lung to stiffen and make breathing even more difficult.
EYES: Eye involvement occurs in about 20 to 30 percent of patients with sarcoidosis, particularly in children who get the disease. Almost any part of the eye can be affected the membranes of the eyelids, cornea, outer coat of the eyeball (sclera), retina, and lens. The eye involvement can start with no symptoms at all or with reddening or watery eyes. In a few cases, cataracts, glaucoma, and blindness can result. Every patient with sarcoidosis should be evaluated by an eye physician (ophthalmologist) at least annually.
SKIN: The skin is affected in about 20 percent of sarcoidosis patients. Skin sarcoidosis is usually marked by small, raised patches on the face. Occasionally the patches are purplish in color and larger. Patches can also appear on limbs, face, and buttocks. Other symptoms include erythema nodosum (red bumps), mostly on the legs and often accompanied by arthritis in the ankles, elbows, wrists, and hands. Erythema nodosum usually goes away, but other skin problems can persist.
NERVOUS SYSTEM: In an occasional case (1 to 5 percent), sarcoidosis can lead to neurological problems. For example, sarcoid granulomas can appear the brain, spinal cord, and facial and optic nerves. Facial paralysis and other symptoms of nerve damage call for prompt treatment.
Chest Film (CXRAY) stages of Sarcoidosis
The term stages can be misleading in that patients do not always progress from a mild case to a more serious case. Stage I does not always progress to stage two, three etc. They do not imply a progression, rather these are patterns seen on chest films. In fact, because these stages were originally defined from chest films, there may not be any significant difference in symptoms, pulmonary function tests or prognosis between Stage I and II. In many cases the disease remits and never returns, regardless of whether in Stage I or II. Generally, most patients with Stage III or IV do have worse disease, symptoms and prognosis but often their chest film overestimates their symptoms.
• Thoracic (hilar and mediastinal) lymphadenopathy
• Normal lung parenchyma
• Enlarged lymph nodes (glands) in the middle of the
These nodes sit outside of the lung. When sarcoidosis affects these or other nodes in the body, they increase in size and become visible on chest film and chest CAT scan. Biopsy of these nodes by mediastinoscopy (scope placed into to the middle of the chest through an incision. This procedure requires general anesthesia)) is one way of defining the diagnosis. Other diseases that can cause these findings are tuberculosis, fungal disease, lymphoma, lung cancer, etc.
• Thoracic (hilar and mediastinal) lymphadenopathy
• Abnormal lung parenchyma
• Enlarged lymph nodes/glands in the middle part of
the chest with abnormal lungs on chest x-ray films
This disease is more extensive than Stage I, because now there is radiographic evidence of lung involvement instead of just node involvement. However, this may be misleading. Most patients, 75 to 95% of those with only Stage I by chest film, have lung involvement on biopsy of the lung. Biopsy of the lung is normally done by bronchoscopy (scope placed down the mouth into the lung. This procedure does not require general anesthesia) Symptoms and Pulmonary function tests may or may not be different between Stage I and II. These findings would suggest that in many patients there is no or minimal difference between Stage I and II.
• Abnormal lung parenchyma
• No lymphadenopathy
• Abnormal lungs on chest film images but no enlarged
lymph nodes/glands in the middle part of the chest
Suggests a later stage of progression and more severe disease (symptoms and pulmonary function tests).
• Permanent lung fibrosis
• Destruction of the lung with damage to upper lobes and scar tissue formation (irreversible lung disease)
No single test can be relied on for a correct diagnosis of sarcoidosis. X-rays and blood tests are usually the first procedures the doctor will order. Pulmonary function tests often provide clues to diagnosis/but are more useful for determining the severity of lung involvement. Other tests may also be used, some more often than others.
CHEST X-RAY: A picture of the lungs, heart, as well as the surrounding tissues containing lymph nodes, where infection-fighting white blood cells form, can give the first indication of sarcoidosis. For example, a swelling of the lymph glands between the two lungs can show up on an x-ray. An x-ray can also show which areas of the lung are affected. Chest x-ray can be classified as Stage I, II, III or IV as described above.
PULMONARY FUNCTION TESTS: Breathing tests called pulmonary function tests (PFT), evaluate how well the lungs are doing their job of expanding and exchanging oxygen and carbon dioxide with the blood. Granulomas and fibrosis of lung tissue may decrease lung capacity and disturb the normal flow of gases between the lungs and the blood. Important PFTs include spirometry (flow rate), lung volumes and diffusion. Occasionally, PFTs during or post-exercise may also be helpful in characterizing the extent and severity of the disease process.
BLOOD TESTS: Blood analyses can evaluate the number and types of blood cells in the body and how well the cells are functioning. They can also measure the levels of various blood proteins known to be involved in immunological activities, and they can show increases in serum calcium levels and abnormal liver function that can accompany sarcoidosis.
Blood tests can measure a blood substance called angiotensin-converting enzyme (ACE). Because the cells that make up granulomas secrete large amounts of ACE, the enzyme levels may be high in patients with sarcoidosis. ACE levels, however, are not always high in sarcoidosis patients, and increased ACE levels can also show up in other illnesses.
BRONCHOALVEOLAR LAVAGE: This tests uses an instrument called a bronchoscope a long, narrow tube with a light at the end to wash out, or lavage, cells and other materials from inside the lungs. This wash fluid is then examined for the amount of various cells and other substances that reflect inflammation and immune activity in the lungs. A high number of white blood cells in this fluid usually indicate an inflammation in the lungs.
BIOSPY: Microscopic examination of tissue specimens can tell a doctor that granulomas typical of sarcoidosis have formed in your body. Specimens of lung tissue are obtained with a bronchoscope, or less often by open chest surgery or a video assisted thorascope (VAT). Biopsies of chest lymph nodes are obtained with a mediastinoscope or less often by open chest surgery or a video assisted thorascope (VAT). Occasionally, tissue specimens are obtained from the eye, skin, or other lymph nodes when involvement of those tissues is suspected. Rarely, sarcoidosis is found in biopsy material of other organs taken for other purposes. Examination of tissue provides a definitive diagnosis.
GALLIUM SCANNING: In this procedure, the doctor injects the radioactive chemical element gallium-67 into the patient's vein. The gallium collects at places in body affected by sarcoidosis and other inflammatory conditions. Two days after the injection, the body is scanned for radioactivity. Increase in gallium uptake at any site in the body indicate that inflammatory activity has developed at the site and also give an idea of which tissue, and how much tissue, has been affected. However, since any type of inflammation causes gallium uptake, a positive gallium scan does not necessarily mean that the patient has sarcoidosis.
KVEIM TEST: This test involves injecting a standardized preparation of sarcoid tissue material into the skin. Biopsy of the lump formed at the point of injection is considered evidence for sarcoidosis. On the other hand, the test result is not always positive in patients with sarcoidosis. The Kveim test is not used often in the United States because no test material has been approved for sale by U.S. Food and Drug Administration. However, a few hospitals and clinics may have some standardized test preparation prepared privately for their own use
SLIT-LAMP EXAMINATION: An instrument called a slit lamp, with permits examination of the inside of the eye, can be used to detect silent damage from sarcoidosis.