Summary

A diagnosis of sarcoidosis is based on suggestive radiographic pattern, presence of non-caseating granulomas and negative fungal and acid-fast bacilli (AFB) cultures. Sarcoidosis usually presents with hilar and/or mediastinal lymphadenopathy and distinct parenchymal radiographic patterns, such as fine nodular, reticulonodular or acinar opacities and rarely focal nodules or masses. A diffuse miliary pattern occurs in less than 1% of cases and can be identical to patterns seen in tuberculosis, fungal infections, histiocytosis and miliary metastases. Here the authors report the case of a 48-year-old man who presented with mediastinal widening and miliary pattern on chest radiograph, initially erroneously treated for tuberculosis. Transbronchial biopsies, bronchoalveolar lavage (BAL) and serological tests were compatible with sarcoidosis, while BAL cultures were negative for fungi and AFB growth. The patient finally demonstrated clinical and radiological remission under corticosteroids. Clinicians should consider sarcoidosis in the differential diagnosis when bilateral miliary-type lesions are revealed on chest X-ray.