A Rhizopus oryzae strain isolated from resected bone and soft tissue specimens from a sinonasal and palatal mucormycosis case. Report of a case and in vitro experiments of yeastlike cell development.

We report a histologically and mycologically proven sinonasal mucormycosis case causing palatal necrosis in a nondiabetic patient with renal failure. Mycological examination of Giemsa stained imprinted tissue preparations revealed abundant yeast-like cells besides the typical mucoraceous hyphae. The fungus was isolated from surgical specimens and identified as Rhizopus oryzae by phenotypic and genotypic tests. Laboratory studies were performed to investigate the association of the yeast-like cells observed in tissue specimens and the fungus recovered in culture. In vitro induced yeast-like cell development of the case isolate was found under certain growth conditions and documented by photomicrographs.