An Unusual Case of Blastomycosis Presenting as "Punched Out" Ulcerations

Background: Cutaneous blastomycosis commonly presents as verrucous, hyperkeratotic nodules or plaques. Less commonly, it presents as ulcerations with accompanying scale crusting or verrucous features. Case Report: A healthy 34-year-old incarcerated male with a history of drug abuse presented with several, well-defined (punched out), deep ulcerating cutaneous lesions with undermined borders. There was no crusting, or verrucous features. The clinical differential diagnoses included pyoderma, vasculitic ulcers, and pyoderma gangrenosum. The histopathology from a gluteal ulceration demonstrated pseudoepitheliomatous hyperplasia with acute, chronic, and granulomatous inflammation. PAS stain of the specimen exhibited thick-walled yeast demonstrating broad-based budding typical of blastomycosis and tissue cultures grew Blastomyces dermatitidis after one month. Conclusion: Ulceration without verrucous features can portend cutaneous blastomycosis. Diagnosis using fungal culture of the wound or tissue takes weeks to result. A prompt biopsy and histopathologic examination or broad-range PCR testing of a wound swab, tissue or urine specimen can lead to a prompt diagnosis.