Phaeohyphomycosis caused by Exophiala jeanselmei in a patient with polymyalgia rheumatica

Abstract

An 87-year-old man, a gardener in Okinawa, first noticed a tumor on the dorsum of his right hand in November 2005. He had been taking prednisolone for the treatment of polymyalgia rheumatica since 2000. A nearby dermatologist incised the tumor for pus drainage in February 2006. In April of the same year, the dome-like tumor reappeared. The same treatment was repeated. Because the culture of the pus revealed fungi at that time, terbinafine hydrochloride and minocycline were administrated under the diagnosis of a deep fungal infection. After a short remission, the tumor recurred in November of the same year and in May and August of 2007 regardless of the repeated incision and pus drainage. He was referred to our hospital on 27 September 2007. His first physical examination at our outpatient office showed a skin-colored, well-demarcated, multilocular, cystic subcutaneous tumor on the dorsum of his right hand. Histopathological examination revealed a pseudocyst with fibrous walls of connective tissue. Continuous, bead-like hyphae, positive with periodic acid-Schiff stain and Grocott stain, were found within the pseudocyst. Morphological and molecular biological examinations of the separately cultured specimens identified the causative agent as Exophiala jeanselmei. The entire cyst was removed under local anesthesia, and an artificial dermis made of silicon membrane was applied to the wound. Skin graft was performed in November after confirming no recurrence of the fungal infection. Terbinafine hydrochloride 125 mg/day has continued. No recurrence has been observed up to now.