Disseminated Scedosporium prolificans: A Case Report and Diagnostic Review
TP Seybt, DG Falls. Medical College of Georgia, Augusta, GA
Background: Opportunistic fungal infections in the immunocompromised host are not uncommon; however, many fungi are morphologically similar presenting a diagnostic challenge with treatment implications. We report an unusual case of disseminated Scedosporium prolificans in a myelofibrosis patient presenting with a left lower lobe pneumonia and effusion. The comparative morphology and alternative methods used to identify Scedosporium spp., Pseudallescheria spp., Aspergillus spp., and Candida spp. are reviewed.
Design: A 49-year-old Caucasian female with a history of cyclic neutropenia and a prior bone marrow biopsy revealing myelofibrosis of uncertain etiology was admitted to our institution for sepsis and left lower lobe pneumonia. The patient subsequently developed respiratory distress. Sepsis workup revealed stool cultures positive for Clostridium difficile as well as blood and sputum cultures positive for an uncommon mold (Scedosporium prolificans), which was verified by the Mayo Clinic in Rochester, MN. The patient was treated with metronidazole for her Clostridium infection; however, her condition continued to worsen requiring vasopressors for cardiovascular support. Upon further deterioration of the patient's health, the family opted to withdraw care and the patient subsequently died. Permission for unrestricted autopsy was granted.
Results: Gross examination at autopsy revealed a bilateral hemorrhagic lobular pneumonia. Multiple small ulcerations were noted involving the mucosa of the stomach, small bowel, and bladder. Microscopic examination revealed evidence of a fungal organism within the tissues of the thyroid and parathyroid glands, right and left lungs, heart, stomach, small bowel, bladder, bone marrow, and brain. Morphology was identified with Hematoxylin and Eosin (H&E), Gomori methenamine silver (GMS), and Periodic Acid Schiff (PAS) staining.
Conclusions: The isolated fungus displayed hyphae measuring 4-6 microns in thickness with dichotomous branching at 45 degrees in a haphazard manner. Multiple conidia were also identified budding from the hyphae. The sputum specimen was sent to the Mayo Clinic where microscopy and colony morphology were performed confirming the presence of Scedosporium prolificans. While this is an uncommon organism, it does possess the ability to grow in an angioinvasive pattern as does Pseudallescheria spp., Aspergillus spp., and some Candida spp. Fungal morphology can appear strikingly similar in the above species; therefore, additional testing may be warranted to correctly identify the causative organism in order to tailor pharmacotherapy.
Monday, March 9, 2009 9:30 AM
Poster Session I Stowell-Orbison/Autopsy Award # 11, Monday Morning