Pulmonary Sarcoidosis Showing a Solitary Large Nodule with a "Pseudo-alveolar" Pattern

An abnormal shadow was detected on chest radiograph in a 28-year-old male on a routine medical check. The chest radiograph showed a solitary mass-like opacity in the right upper lung field. The patient attended our hospital for further examination on May 22, 2002. High-resolution computed tomography showed an aggregate of micronodular opacities consistent with the "pseudo-alveolar" pattern described in recent reports. The final diagnosis was pulmonary sarcoidosis as confirmed by the presence of epithelioid granulomas in specimens from transbronchial lung biopsy. Pulmonary sarcoidosis with a pseudo-alveolar pattern is unusual, particularly in the absence of bilateral hilar lymphadenopathy. Therefore, this case might be instructive for the diagnosis of pulmonary sarcoidosis