Blastomycosis-like pyoderma: A pitfall for the misdiagnosis of squamous cell carcinoma

Blastomycosis-like pyoderma is a rare cutaneous disease presenting as solitary or multiple verrucous or ulcerated plaques and nodules in a susceptible patient. The diagnostic criteria include characteristic verrucous plaques with pustules and elevated borders, histopathologic findings of pseudoepitheliomatous hyperplasia with abscesses, growth of at least one bacterium in tissue culture, and exclusion of other infectious sources. This report describes a case of a 62-year-old man with poorly controlled type 2 diabetes mellitus who presented with plaques, nodules, and ulcers in both groins and the right ankle. The patient was initially misdiagnosed with multiple squamous cell carcinomas and underwent several operations. A review of the pathology slides revealed pseudoepitheliomatous hyperplasia with multiple dermal abscesses, while repeated wound and tissue cultures were positive for coagulase-negative Staphylococcus. Blastomycosis-like pyoderma was diagnosed. The patient was subsequently treated with culture-guided prolonged antibiotic therapy followed by intralesional steroid injection, which led to gradual resolution of the lesions.