Phaeohyphomycosis Infections in Solid Organ Transplant Recipients The Largest Single Institution Experience
EN Beckman, JB Garcia-Diaz, GE Loss, JS Schieffelim, CG Staffeld-Coit, JC Garces, RA Keller, GA Pankey. Ochsner Clinic Foundation, New Orleans, LA
Background: Phaeohypomycotic infections are relatively common in solid organ transplant recipients. Awareness of the characteristic morphology is important in prompt treatment and if the lesion was not cultured.
Design: Specimens were reviewed years 1988-2005 from 24 patients with solid organ transplants and Phaeohypomycosis infection.
Results: Biopsy material from the skin and subcutaneous tissue was most common (38 separate specimen.) The typical histologic appearance was one of purulent granulomas with central acute inflammation, surrounding granulomatous change with varying number of giant cells and peripheral inflammaton and fibrosis. In older lesions, the granulomatous quality was less-well defined, and there was more fibrosis and chronic inflammation. Varying numbers of brown fungal forms were evident with H&E stains. 25 of the 38 had visible brown fungus, although in a minority of cases the organisms were only faintly brown. The most intensely brown structures were yeast. In 13 specimens, the organisms were only seen with a special stain. Fungi were consistently positive with the GMS, PAS, and Fontana-Masson stains, although the GMS stain was the one commonly used. Fungal forms varied and include forms that were simple mycelial, mycelial with bulbous distention, mycelial and yeast, and only yeast. Fungal forms, especially mycelial, tended to be within giant cells. 8 of the 38 skin and subcutaneous specimens consisted of only deeper tissue. Of the 30 specimens that were not exclusively deep, pseudoepitheliomatous hyperplasia of the epidermis was present in 20. That hyperplasia was mild in 8, moderate in 4, and pronounced in 8. In one specimen this proliferation was very difficult to distinguish from well-differentiated squamous carcinoma. A brain and a lung specimen both had purulent granulomas with brown fungi. 2 specimens were lung cytology specimens which contained brown fungi. Fungi of al specimen were compatible with forms of Phaeohypomycosis (culture confirmed in 20 patients).
Conclusions: In cases of possible Phaeohypyhomycosis infection, culture of the specimen is highly desirable. Still, definitive diagnosis can usually be made based upon the morphology.
Monday, March 9, 2009 1:00 PM
Poster Session II # 188, Monday Afternoon