Medical disclaimer: This page is for educational purposes only. It does not replace the advice of a qualified doctor. If you have been told you may have sarcoidosis, please consult a respiratory specialist. Last reviewed May 2026 by Dr. Kunal Waghray, MD DM DNB MNAMS EDRM.
What Is Sarcoidosis?
A young man in his thirties is admitted to an ICU with severe COVID-19 and recovers after several weeks on a ventilator. Months later, a routine chest X-ray shows enlarged lymph nodes around both lungs. A physician starts him on anti-TB treatment. Six months pass. The nodes have not changed. The sputum tests were negative. The patient has not improved.
A respiratory specialist refers him for EBUS-TBNA. The lymph node biopsy shows non-caseating granulomas. No acid-fast bacilli. No evidence of tuberculosis. The diagnosis is sarcoidosis.
This is not an unusual story in India. Sarcoidosis and tuberculosis share enough features on a chest X-ray that one is frequently mistaken for the other. This page explains what sarcoidosis is, how it differs from TB, and what the diagnostic process involves.
What Is Sarcoidosis?
Sarcoidosis is a condition in which clusters of inflamed cells called granulomas form in one or more organs. Most commonly these granulomas appear in the lungs and the lymph nodes around the lungs, but sarcoidosis is a systemic disease — it can involve the skin, eyes, heart, liver, kidneys, and nervous system.
The cause is not fully understood. Sarcoidosis is thought to result from an abnormal immune response to an unidentified trigger in genetically susceptible individuals. It is not infectious. You cannot catch it from another person.
The defining feature of sarcoidosis under the microscope is the non-caseating granuloma: a compact cluster of immune cells without necrosis at its centre. This is what distinguishes sarcoidosis from tuberculosis, which forms caseating granulomas (with a necrotic, cheese-like centre).
Why Sarcoidosis Is Often Mistaken for Tuberculosis in India
India has one of the highest TB burdens in the world. When a chest X-ray shows bilateral hilar lymphadenopathy — enlarged lymph nodes on both sides of the mediastinum — the first thought in most Indian clinical settings is TB. This is a reasonable starting point, but sarcoidosis produces an identical radiological picture.
The practical consequence is that patients with sarcoidosis are sometimes started on anti-TB treatment before a tissue diagnosis is obtained. Anti-TB drugs do not improve sarcoidosis. If symptoms persist or the imaging does not change after several months of treatment, sarcoidosis should be reconsidered and a biopsy should be obtained.
What Are the Symptoms of Sarcoidosis?
Symptoms vary considerably depending on which organs are involved and the extent of disease. Many patients have mild or no symptoms and are diagnosed when a chest X-ray or CT is done for another reason.
When pulmonary sarcoidosis is symptomatic, the most common complaints are:
- Breathlessness on exertion
- A dry, persistent cough that does not respond to inhalers
- Chest tightness or discomfort
- Fatigue disproportionate to the degree of lung involvement
Extrapulmonary features include skin lesions (erythema nodosum or lupus pernio), eye symptoms (blurred vision, redness, photophobia from uveitis), and joint pain. The combination of erythema nodosum, bilateral ankle arthritis, and bilateral hilar lymphadenopathy is called Löfgren syndrome and carries an excellent prognosis with a high rate of spontaneous remission.
Scadding Stages: How Sarcoidosis Is Classified on Imaging
The Scadding classification describes the radiological appearance on chest X-ray. It is a staging system for imaging, not a measure of disease severity or prognosis in isolation.
Stage II is the most common presentation in Indian patients at the time of diagnosis, based on published cohort data (PMC8926222).
How Is Sarcoidosis Diagnosed?
There is no single blood test that confirms sarcoidosis. Serum ACE (angiotensin-converting enzyme) is elevated in many patients but lacks both sensitivity and specificity. It cannot be used to diagnose or exclude sarcoidosis on its own.
Diagnosis requires three elements working together: a clinical and radiological picture consistent with sarcoidosis, histological evidence of non-caseating granulomas from a tissue biopsy, and exclusion of other causes of granulomatous disease (particularly TB and fungal infections).
For patients with mediastinal or hilar lymphadenopathy, the preferred sampling method is EBUS-TBNA (endobronchial ultrasound with transbronchial needle aspiration). This bronchoscopic technique samples lymph nodes through the airway wall under direct ultrasound guidance, without the need for surgery or general anaesthesia. For skin or peripheral lymph node involvement, biopsy from those sites is often simpler and equally diagnostic.
When mediastinal disease is not accessible by EBUS, medical thoracoscopy can sample pleural tissue. For a detailed explanation of the diagnostic workup and what the procedure involves, see the sarcoidosis diagnosis page.
Does Sarcoidosis Need Treatment?
Not always. For patients with Stage I or II disease and mild or no symptoms, active monitoring without medication is appropriate. Approximately 60 to 70 percent of these patients achieve spontaneous remission within two to three years.
Treatment is initiated when there is progressive or symptomatic pulmonary disease, significant extrapulmonary involvement (cardiac, neurological, or ocular), or Scadding Stage III or IV on imaging. The first-line agent is oral prednisolone (corticosteroid therapy). Treatment is typically maintained for one to two years with gradual dose reduction.
For patients who do not respond to steroids or who cannot tolerate them long-term, second-line agents including methotrexate and hydroxychloroquine are used. A small proportion of patients with refractory disease require biological therapies.
Frequently Asked Questions
Is sarcoidosis the same as tuberculosis?
No. Both can cause bilateral hilar lymphadenopathy on a chest X-ray, and both involve granulomas in the lung. The critical difference is that TB granulomas are caseating (they have a necrotic centre), while sarcoidosis granulomas are non-caseating. TB is caused by Mycobacterium tuberculosis and is infectious. Sarcoidosis is not infectious and is not caused by a bacterium. They require entirely different treatments.
Can sarcoidosis go away on its own?
Yes, in many cases. Approximately 60 to 70 percent of patients with Stage I or II sarcoidosis achieve spontaneous remission without treatment. The Löfgren syndrome presentation — erythema nodosum, ankle arthritis, and bilateral hilar enlargement — has a particularly high remission rate. However, some patients develop chronic or progressive disease that requires corticosteroid therapy.
What is the most common symptom of sarcoidosis?
In pulmonary sarcoidosis, the most common symptom is breathlessness on exertion. Many patients also report a dry cough that does not respond to inhalers or antibiotics. Fatigue is common. Some patients have no respiratory symptoms at all and are picked up incidentally on a chest X-ray done for another reason.
How is sarcoidosis diagnosed?
Diagnosis requires three things: a compatible clinical and radiological picture, histological evidence of non-caseating granulomas from a biopsy, and exclusion of other causes of granulomatous disease (particularly tuberculosis). In India, EBUS-TBNA is the most commonly used sampling method for mediastinal or hilar sarcoidosis, as it can sample lymph nodes without surgery.
Does sarcoidosis affect organs other than the lungs?
Yes. Sarcoidosis is a systemic disease that can involve the skin, eyes, heart, liver, kidneys, and nervous system. Skin involvement appears as erythema nodosum (tender red nodules) or lupus pernio (violet plaques on the face). Eye involvement, particularly uveitis, can cause visual impairment if untreated. Cardiac sarcoidosis, though less common, can cause arrhythmias and is a serious complication.
Is sarcoidosis more common in India than elsewhere?
Sarcoidosis occurs globally, but its presentation in India has distinct features. The Indian cohort literature suggests a higher proportion of younger patients at diagnosis, frequent skin and eye involvement, and a strong overlap with TB that complicates diagnosis. A study of 327 Indian patients (PMC8926222) documented the clinical pattern at a tertiary centre.
What happens if sarcoidosis is not treated?
For the majority of patients, sarcoidosis is mild and self-limiting. However, a minority develop progressive pulmonary fibrosis, which causes irreversible lung damage and impaired function. Cardiac and neurological involvement, if missed, can be serious. Regular follow-up is important to identify the small proportion of patients whose disease is progressing.
Get a Confirmed Diagnosis in Hyderabad
If a chest X-ray or CT has shown bilateral hilar lymphadenopathy, if you have been on anti-TB treatment without improvement, or if a respiratory specialist has raised the possibility of sarcoidosis, the next step is a tissue diagnosis. Without histology, the diagnosis cannot be confirmed.
Dr. Kunal Waghray, MD DM DNB MNAMS EDRM, is an interventional pulmonologist at Respire Airway Clinics, Basheer Bagh and Jubilee Hills, Hyderabad. He performs EBUS-TBNA and medical thoracoscopy for sarcoidosis diagnosis and provides specialist follow-up for confirmed cases. Referrals are welcome from chest physicians, general practitioners, and oncologists.
Clinical References
- Clinical profile of sarcoidosis: a study of 327 patients from a tertiary care centre in India. Lung India. 2022. PMCID: PMC8926222.
- Sarcoidosis in India: clinical, radiological, and functional profile. Lung India. 2012. PMCID: PMC3698001.