It's been quite awhile since I posted a challenging case, so here it goes.
Clinical history: 43-year-old woman with recent onset of persistent hoarseness presents to local ENT surgeon who sees an exophytic lesion on the true vocal cord on endoscopic. Biopsies were taken to confirm the clinical impression of early well-differentiated squamous cell carcinoma. Low-power examination showed papillary thickening of the epithelium with minimal atypia.
Higher power showed a mixed-inflammatory infiltrate:
High power examination showed epithelioid cells and round refractile structures, some with internal structures.
A GMS stain was performed:
On the basis of the morphology, budding, and size, a diagnosis of laryngeal blastomycosis was made.
The literature has sporadic reports of laryngeal blastomycosis and paracoccidiomycosis and the last report of a large single-institution series was in 1993 from the Mayo Clinic (Reder PA, Neel HB. Blastomycosis in otolaryngology: review of a large series. Laryngoscope 1993;103:53-58.) The consistent theme is that laryngeal blastomycosis is a mimic of squamous cell carcinoma in the larynx, similar to cutaneous lesions associated with pseudoepitheliomatous hyperplasia. This patient had no history suggesting a recent unusual exposure or immunosuppression. Certainly, disseminated infection with Blastomyces involving the larynx is unusual but, especially in endemic areas in the U.S., consideration of laryngeal involvement is worth considering if there is minimal atypia or the clinical or endoscopic findings aren't concordant.