Clinical and radiological features of tuberculosis and sarcoidosis are quite overlapping and therefore, a diagnostic dilemma often persists. Exclusion of tuberculosis is important, particularly because corticosteroids form the mainstay of treatment for sarcoidosis. Cavity formation is common in tuberculosis and uncommon in sarcoidosis.
Both tuberculosis and sarcoidosis are granulomatous diseases, however, tuberculosis has a caseating granuloma as opposed to sarcoidosis, which present with non-caseating epithelioid cell granuloma.
Whereas some consider sarcoidosis and tuberculosis as two extremes of the same disease process, other researchers have negated the role of mycobacteria in causation of sarcoidosis. The balance of evidence favors mycobacteria or their products as a trigger for inciting immune responses leading to sarcoidosis in a proportion of patients, which is likely to be higher in countries with high tuberculosis burden.
Also, there is a term called Tuberculous Sarcoidosis. Tuberculous Sarcoidosis. Set-up of tuberculous sarcoidosis shows three patterns:
(1) patients who has had tuberculosis and develop sarcoidosis
(2) patients who present with co-existent sarcoidosis and tuberculosis
(3) patients of chronic sarcoidosis who develop overt tuberculosis.
Tuberculous sarcoidosis has clinical manifestations of both diseases but the course is different and so also the treatment which is the combinations of steroids in large doses prescribed for the specific treatment of sarcoidosis with anti tuberculosis drugs.