Acute respiratory distress syndrome (ARDS) secondary to Blastomyces dermatitidis masquerading as a malignancy: A case report and clinical pearls

Abstract

A 73-year-old woman with type 2 diabetes presented with progressive hypoxemia requiring intubation. Her diagnosis was thought to be secondary to metastatic malignancy based on imaging. A high-risk biopsy was obtained using endobronchial ultrasound (EBUS), while intubated and requiring 100% oxygen. Pathological samples were negative for malignancy but demonstrated broad-based budding yeast, consistent with Blastomyces dermatitidis. Blastomyces is endemic in North America around river valleys with recent increasing incidence. Respiratory illness akin to pneumonia is typical, severe disease usually occurs in immunocompromised hosts. Our case is unique in its fulminant respiratory failure in a mildly immunocompromised individual with well-controlled diabetes. We also describe challenges associated with acquiring tissue samples, and the importance of pathological sampling for diagnosis and avoiding premature closure bias. Although rare, as both blastomycosis and immunocompromising therapies become more common, risk of severe blastomycosis is increased; it must therefore be on the differential of nonresolving pneumonia or acute respiratory distress syndrome (ARDS).