A case of concomitant tuberculosis and sarcoidosis with mycobacterial DNA present in the sarcoid lesion.

A 35-year-old Chinese woman initially presented with histologically and bacteriologically confirmed tuberculous lymphadenitis. She was also found to have thrombocytopenia, elevated serum alkaline phosphatase, and bilateral lung infiltrates. After 15 months of antituberculosis treatment, despite resolution of the cervical lymphadenopathy, she started to experience dyspnea. Chest radiograph appearance, thrombocyte count, and liver biochemistry had all deteriorated as well. Histologic findings from tissues obtained via transbronchial biopsy and open lung biopsy were consistent with sarcoidosis but also showed the presence of mycobacterial DNA by the polymerase chain reaction. She subsequently achieved a very good response clinically, radiographically, hematologically, and biochemically with 1-year of corticosteroid treatment for her sarcoidosis, and she remained relapse-free afterwards. The concomitant presence of tuberculosis and sarcoidosis in this patient together with the presence of mycobacterial DNA in the sarcoid lesion reiterate the possibility that mycobacteria or some of its components may be capable of inducing the immune response and the pathologic changes of sarcoidosis.