Laryngeal presentation of blastomycosis.

Systemic blastomycosis may rarely involve the larynx, and it most likely is a result of hematogenous dissemination or direct inoculation from a currently or previously active pulmonary infection. Often, laryngeal blastomycosis has been confused with squamous cell carcinoma because of the clinical and histopathologic similarities, and this confusion has led to inaccurate diagnosis and inappropriate therapy. The etiologic agent, Blastomyces dermatiditis, may be seen in infected tissue with routine and special stains; however, cultural proof remains the sine qua non for diagnosis.