Acute Hypoxemic Respiratory Failure as the Initial Manifestation of Alveolar Sarcoidosis: A Rare Case Report.

Alveolar sarcoidosis is an uncommon radiographic phenotype that can closely mimic infection, organizing pneumonia, and malignancy. We report a 44-year-old nonsmoker with 1 month of dyspnea, fever, and cough. Computed tomography of the chest showed patchy subpleural consolidations with perilymphatic nodules and interstitial thickening. Microbiologic testing, including bacterial and fungal cultures, and GeneXpert MTB, were negative; autoimmune serologies were unremarkable. Pulmonary function tests revealed a restrictive pattern. Bronchoalveolar lavage was lymphocytic, and transbronchial lung biopsy demonstrated noncaseating granulomas with elevated serum ACE levels that was suggestive of acute alveolar sarcoidosis. After initiating the treatment with prednisone, symptomatic, functional, and radiographic improvements were noticed. This case underscores the need for integrated clinical, imaging, and histologic assessment to identify sarcoidosis presenting as acute hypoxemic respiratory failure with an alveolar pattern.