Fatal Ultra-Early-Onset Rhino-Cerebral Mucormycosis Caused by Rhizomucor miehei Following Umbilical Cord Blood Transplantation and Review of Published Literature.

A 43-year-old man with myelodysplastic syndrome underwent umbilical cord blood transplantation (CBT). On day 4 post-transplantation, he developed right periorbital pain and oculomotor nerve palsy. Brain MRI revealed fluid accumulation in the sphenoid sinus and mucosal thickening in the right maxillary sinus. Given the extraordinarily early onset and neurological involvement, fungal meningitis, including mucormycosis, was suspected, and empirical high-dose liposomal amphotericin B (10 mg/kg/day) was initiated. Nasal discharge culture yielded Rhizomucor species, later identified as Rhizomucor miehei by polymerase chain reaction (PCR). Despite aggressive antifungal therapy, the patient's neurological condition deteriorated, and he died on day 49. Autopsy confirmed extensive rhino-cerebral mucormycosis with angioinvasion, and Mucorales DNA was detected in brain tissue by quantitative PCR. To our knowledge, this represents the first reported case of R. miehei infection occurring within days after transplantation, preceding neutrophil engraftment. This case highlights the importance of recognizing mucormycosis even in the immediate post-transplant period and underscores the limitations of antifungal therapy in the absence of surgical debridement.