Hepatosplenic mucormycosis due to Rhizomucor pusillus identified by panfungal PCR/sequencing of ribosomal ITS2 and LSU regions in a patient with acute myelogenous leukemia: A case report

Abstract

Background: Angioinvasive Rhizomucor pusillus infection with dissemination to the liver and spleen is exceedingly uncommon, representing less than 1% of reported cases of mucormycosis. Methods: Diagnosis of mucormycosis is often difficult using conventional methods that rely on broad-based non-septate hyphae present on histologic examination and morphological identification of the cultured organism. Our laboratory also uses an in-house panfungal molecular assay to rapidly diagnose invasive fungal infection when conventional methods do not provide definitive results. Results: Herein we present a case of disseminated mucormycosis with hepatosplenic involvement in a 49-year-old female with acute myelogenous leukemia following induction chemotherapy. But in this case repeated tissue biopsy cultures were negative. R. pusillus infection was diagnosed using an in-house panfungal PCR/sequencing assay based on dual priming oligonucleotide primers. Conclusions: New molecular assays facilitate prompt diagnosis of invasive fungal infections.