Rhinocerebral Mucormycosis Caused by Rhizopus Oryzae in a Patient with Acute Myeloid Leukemia: A Case Report

BACKGROUND Rhinocerebral mucormycosis（RCM） is a rare fatal fungal infection which is on the increase among immunocompromised hosts such as patients who have had hematological cancers, or have received immunosuppressive drugs, corticosteroids, or other T cell suppressing agents.CASE SUMMARY We report a case of RCM caused by Rhizopus oryzae, one of the most common opportunistic pathogens, in a patient suffering from a fourth relapse of acute myeloid leukemia. The patient developed RCM after he had received long-term antibiotic agents and corticosteroids. The pathogen was isolated three times from nasal secretions collected from the deep parts of the nasal cavity and was identified by morphology and internal transcribed spacer sequencing. Blood infection was excluded by droplet digital polymerase chain reaction and blood culture. The patient was empirically treated with caspofungin and voriconazole for several days while the lesions continued to progress. The patient was given amphotericin B in combination with caspofungin after RCM was suspected, and the lesions improved over the course of treatment, which lasted several days. However, the patient eventually died of the primary disease.CONCLUSION This case indicates that immunosuppressive drugs, including corticosteroids and antimetabolites in hematological tumor, do increase the risk of infections of this type. Early diagnosis, prompt and frequent surgical debridement, and treatment with amphotericin B without delay are all essential in combatting RCM.