[Solitary nodular sarcoidosis demonstrating reversed tuberculin skin reaction]

A 29-year-old woman was admitted because of chest radiograph abnormality. She had no respiratory complaints. Chest CT demonstrated an ill-defined nodule of 20mm with the "sarcoid galaxy sign" in the right upper lobe. Transbronchial biopsy (TBB) specimens from right S2 revealed non-caseating epithelioid cell granuloma. Initial clinical findings suggested mycobacterial infection. However, while waiting for the results of mycobacterial cultures in bronchial washing fluid, the tuberculin skin reaction was found to be negative, and enlargement of nodule, mediastinal lymphadenopathy and elevated soluble IL-2R were observed. Cultures for mycobacterium were negative and repeat TBB specimens revealed granulomatous inflammation. We diagnosed with sarcoidosis based on these findings. Solitary nodular sarcoidosis is rare with only 17 cases having been reported. These cases were diagnosed with difficulty because of non-specific clinical findings and of the 17, 16 cases (94%) were diagnosed by surgical procedures. We observed the clinico-radiological course of solitary nodules and the change in tuberculin reaction. Although a negative tuberculin skin reaction was commonly recognized in sarcoidosis patients, we confirmed that initial positive tuberculin reaction changed to negative according to disease progress. To the best of our knowledge, this is the first case report in adults.