A rare case of the coexistence of latent tuberculosis and necrotizing sarcoid granulomatosis with atypical presentation

Abstract

Nodular sarcoidosis comprises less than 5% of cases of sarcoidosis and predominantly shows pulmonary infiltrations. Necrotizing sarcoid granulomatosis (NSG) was first described in 1973 by Liebow, and is best characterized as a variant of nodular sarcoidosis. NSG has the unique picture of infarction-like necrosis within granulomatous lesions, thereby posing a challenge of differentiating it from tuberculosis. Essentially, the diagnosis relies heavily on exclusion of possible causes of granulomatous inflammation. A 35-year-old man with fever and night sweating presented a personal history of significant exposure to pulmonary tuberculosis. His father, with whom he had close contact, had been diagnosed with open tuberculosis 6 months before onset of his symptoms. The sputum acid-fast stain and mycobacterial cultures for tuberculosis were both negative; however, a tuberculin skin test with purified protein derivative was positive by an increment of induration greater than 15 mm. Chest computed tomography (CT)