Chromoblastomycosis is a tropical subcutaneous mycosis. The pathognomonic tissue finding on KOH/biopsy is:
- A Broad-based budding yeast with thick wall
- B Muriform (sclerotic) bodies — dark brown spherical cells with transverse septa ✓
- C Hyphae with right-angle branching and non-pigmented walls
- D Yeast cells within macrophages (Leishman-Donovan bodies)
Correct answer: B. Muriform (sclerotic) bodies — dark brown spherical cells with transverse septa
Explanation
Chromoblastomycosis is caused by dematiaceous (melanin-pigmented) fungi including Fonsecaea pedrosoi. The pathognomonic finding is the muriform body (also called a Medlar body or copper penny): thick-walled, dark brown, spherical cells dividing by septation in multiple planes, giving a cross-shaped (sclerotic) appearance. These are seen in tissue and scraping. Broad-based budding yeast describes Blastomyces dermatitidis; right-angle branching describes Aspergillus; Leishman-Donovan bodies are the amastigote forms of Leishmania.
Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.