Sarcoidosis during treatment of pulmonary tuberculosis: a rare case report and review of the literature

The coexistence of pulmonary tuberculosis and pulmonary sarcoidosis is rare. Further, the morphological features of pulmonary tuberculosis with comorbid pulmonary sarcoidosis are similar to those of tuberculosis alone. There are obvious clinical, histological, and radiological similarities between sarcoidosis and tuberculosis, which makes differential diagnosis very challenging, particularly in countries with a high burden of tuberculosis. Here, a rare case of computed tomography (CT) findings of sarcoidosis that developed during tuberculosis treatment is reported. The 46-year-old male patient had no significant symptoms and was undergoing treatment for Mycobacterium tuberculosis infection. Chest CT revealed enlargement of multiple lymph nodes, without cystic or necrotic changes, in the mediastinum and both hili, and post-infectious changes consistent with the sequelae of tuberculosis infection in the left upper lobe. Chest radiographic evidence was accompanied by compatible clinical features and noncaseating granulomas on biopsy. As the patient was clinically stable, corticosteroid treatment was not initiated. To date, the patient remains without specific symptoms and outpatient follow-ups continue. Although rare, sarcoidosis may occur during treatment of pulmonary tuberculosis, and requires attention for diagnosis and treatment. The present case draws a radiological picture of how tuberculosis evolved to sarcoidosis.