Pulmonary blastomycosis: filamentous forms in an immunocompromised patient with fulminating respiratory failure

A 72-year-old woman with Sjögren's syndrome manifested acute fulminating respiratory failure and was treated with high-dose corticosteroids. Autopsy revealed overwhelming pulmonary infection by Blastomyces dermatitidis with no evidence of extrapulmonary dissemination. Hyphal forms, usually not observed in vivo, were noted in premortem sputum samples as well as in sections of lung obtained at autopsy. It is proposed that the immunocompromised state of the patient played a pathogenetic role in the fulminating clinical course as well as in the production of filamentous forms of B. dermatitidis.