Unilateral renal mucormycosis in a patient presenting with pyelonephritis and acute kidney failure: A case report.

Key Clinical Message: Unilateral renal mucormycosis is a rare infection that should be suspected in patients with recurrent renal infections presenting nonspecific clinical features that do not respond to conventional therapies, especially in impaired immune systems due to related risk factors. Moreover, histopathological examinations should be performed to confirm the diagnosis. For treatment, the preference is that the patient is hospitalized, and surgical intervention and rapid administration of intravenous antifungals for 2-3 weeks are the treatment choices. After discharge, the patient should be followed up with periodic blood urea nitrogen and creatinine levels and, if needed, an imaging modality such as a CT scan or sonography.

Abstract: Renal mucormycosis (RM) is a rare form of mucormycosis infection and is more often in immunocompromised patients with risk factors. Unilateral renal involvement is infrequent in patients and is available as case reports. This condition usually presents with renal colic, fever and chills, and oliguria and has a high mortality rate. Herein, we report a case of unilateral renal mucormycosis presenting with pyelonephritis and acute kidney injury in a 32-year-old patient. The patient had numerous urological procedures in previous years due to nephrolithiasis state, which put him in an immunocompromised state. The histopathological examination of the pylocalyceal system revealed a collection of broad non-septated fungal hyphae branching at 90° accompanied by numerous neutrophils and necrotic tissue in favor of mucormycosis. He was successfully treated with 5 mg/kg/day Liposomal Amphotericin B for 3 weeks, discharged with good general condition, and remained asymptomatic for 3 months after discharge. The diagnosis of RM relies on solid clinical suspicion, which can be authenticated by histopathological examination, and the combination of antifungal therapy and surgical intervention can result in a good outcome.