Sarcoidosis is a relatively uncommon disease which in India, has been more commonly diagnosed in the last few years. Unlike diseases such as asthma, tuberculosis, pneumonias and lung cancer, sarcoidosis is rather an unfamiliar term amongst patients. It is somewhat difficult to understand and appreciate the nuances of sarcoidosis.
A patient with sarcoidosis may present with varied manifestations. Commonly, there are symptoms of low grade fever, weakness, malaise, joint pains, dry cough and/or breathlessness. Sometimes, the patient is entirely asymptomatic and the diagnosis is made incidentally on chest x-ray examination. While lungs are the most frequently involved organs, skin, eyes, liver, spleen and nervous system are the other common sites of disease. Almost any part of the body can be involved in sarcoidosis.
The exact cause of sarcoidosis is not known. This is quite enigmatic for both the patient and the doctor to accept a relatively indefinable disease. It is an immunological disorder but the exact aberrations are not known. There are a number of clinical, radiological and histopathological similarities with tuberculosis. But tuberculosis and sarcoidosis are two distinct diseases with entirely different treatments.
Sarcoidosis is generally suspected on clinical and radiological criteria. The diagnosis is confirmed on histopathological findings of biopsies from the involved organs, for example the lungs, lymph nodes or liver (etc.). Bronchoscopy, and often endo-bronchial ultrasound (EBUS) guided fine needle aspirations are required to obtain biopsy material from the lungs and the lymph nodes. It is important to confirm the diagnosis in view of the treatment issues involving the use of corticosteroids, generally for prolonged periods. It is also important to exclude other diseases such as tuberculosis and lymphomas.
Sarcoidosis is a treatable disease, but recurrences may occur. Strict monitoring is required for side-effects of drugs such as the corticosteroids, during the treatment. The response to the treatment is fairly good. Recurrence of disease requires treatment with alternate drugs which may not be as effective as the corticosteroids.
Sarcoidosis involving the heart and the nervous system is considered as more serious. In chronic cases, sarcoidosis may result in diffuse lung fibrosis and respiratory disability. These cases respond poorly to standard modes of therapy. Overall prognosis of sarcoidosis is generally good provided the disease is diagnosed before any permanent damage has occurred.
A considered decision is always important before the treatment is instituted. These cases are diagnosed with the help of biopsies from the involved organ/s. Most often, they need fiberoptic bronchoscopy to obtain transbronchial and endo-bronchial lung biopsy. This is particularly so because the sarcoidosis treatment requires corticosteroid administration, which are avoided in case there is the possibility of an alternate diagnosis, such as tuberculosis (or lymphomas).EBUS guided fine needle aspiration biopsy adds to the accuracy of obtaining tissues especially in case only the thoracic lymph nodes are involved.
We at our centre, see around 1-2 new cases of sarcoidosis every week, the diagnostic success with bronchoscopic procedures is almost 100 percent. This further emphasizes the frequency of its occurrence and the need for proper diagnosis.