Crust from a cauliflower-like lesion on the hand with brown spherical bodies 6-12 mm in diameter, and after 3 weeks a slow-growing black mold on Sabouraud dextrose agar with Sporulation similar to Cladosporium, Phialophora and Fonsecaea. The probable identification is:

Crust from a cauliflower-like lesion on the hand with brown spherical bodies 6-12 mm in diameter, and after 3 weeks a slow-growing black mold on Sabouraud dextrose agar with Sporulation similar to Cladosporium, Phialophora and Fonsecaea. The probable identification is:

• A. Fonsecaea pedrosoi
• B. Cladosporium cladosporioides
• C. Phialophora verrucosa
• D. Pseudallescheria boydii

Answer: (A)

This presentation fits chromoblastomycosis, a chronic subcutaneous fungal infection caused by dematiaceous (pigmented) fungi. A cauliflower-like crust on the hand is a classic clinical clue, and the tissue shows Medlar bodies (sclerotic bodies): brown, thick-walled, round structures about 5–12 μm in diameter that look like copper pennies. These sclerotic bodies are the hallmark that confirms the diagnosis of chromoblastomycosis, regardless of which pigmented species is involved. When cultured on Sabouraud dextrose agar, the organisms grow as slow-growing, black or dark mold, consistent with dematiaceous fungi. Among the common etiologic agents, Fonsecaea pedrosoi is the most frequent cause of chromoblastomycosis and is the archetype associated with this combination of clinical and histopathologic features. Phialophora verrucosa and Cladosporium cladosporioides can produce similar infections, but Fonsecaea pedrosoi best fits this presentation. Pseudallescheria boydii is more typically linked to eumycetoma rather than chromoblastomycosis.

This presentation fits chromoblastomycosis, a chronic subcutaneous fungal infection caused by dematiaceous (pigmented) fungi. A cauliflower-like crust on the hand is a classic clinical clue, and the tissue shows Medlar bodies (sclerotic bodies): brown, thick-walled, round structures about 5–12 μm in diameter that look like copper pennies. These sclerotic bodies are the hallmark that confirms the diagnosis of chromoblastomycosis, regardless of which pigmented species is involved. When cultured on Sabouraud dextrose agar, the organisms grow as slow-growing, black or dark mold, consistent with dematiaceous fungi.

Among the common etiologic agents, Fonsecaea pedrosoi is the most frequent cause of chromoblastomycosis and is the archetype associated with this combination of clinical and histopathologic features. Phialophora verrucosa and Cladosporium cladosporioides can produce similar infections, but Fonsecaea pedrosoi best fits this presentation. Pseudallescheria boydii is more typically linked to eumycetoma rather than chromoblastomycosis.