Disseminated tuberculosis with acute respiratory distress syndrome lacking granuloma formation in the lung

A 66-year-old woman, who had been treated with systemic corticosteroids for four months for vasculitis of unknown etiology, was referred to our department due to a fever, dyspnea and patchy ground-glass opacities on chest computed tomography. As transbronchial biopsy specimens were suggestive of interstitial pneumonia, the prescribed dose of corticosteroids was increased. However, the patient developed pyrexia and presented diffuse ground-glass attenuation in the lungs bilaterally. Antituberculous drugs were administered because a previous blood interferon-gamma release assay was positive, however, the patient died of severe respiratory failure within several days, and cultures of her blood, urine and bone marrow posthumously revealed Mycobacterium tuberculosis. An autopsy revealed multiple foci of air-space pneumonia containing numerous acid-fast bacilli without granuloma formation, accompanied by diffuse alveolar damage. An immunosuppressive condition might inhibit air-space pneumonia to become granulomatous inflammation as an initial stage of pulmonary tuberculosis.