Laryngeal blastomycosis: a commonly missed diagnosis. Report of two cases and review of the literature.

Blastomycosis is a relatively uncommon fungal disease that most commonly affects the lungs. Other organs may be involved, usually secondary to dissemination of the organism. Laryngeal blastomycosis may occur in isolation from active pulmonary disease. The signs, symptoms, clinical features, and pathological findings of laryngeal blastomycosis mimic those of squamous cell carcinoma. Misdiagnosis may result in inappropriate treatment with potential morbidity. Proper understanding of the clinical presentation and familiarity with the histopathologic features of this disease are therefore imperative. In this paper, we report 2 cases of laryngeal blastomycosis, 1 of which was misdiagnosed as squamous cell carcinoma, clinically and microscopically, with consequent radiotherapy and laryngectomy. In the other case, a clinical diagnosis of glottic squamous cell carcinoma was rendered. However, blastomycosis was identified in a biopsy specimen. We also review cases of isolated laryngeal blastomycosis that have been reported in the English-language literature during the last 80 years. A number of those cases were misdiagnosed clinically and microscopically as squamous cell carcinoma.