A Fatal Case of Isolated Renal Mucormycosis in an Immunocompetent Male

Mucormycosis (MM) is an angio-invasive fungal infection that often presents in immunocompromised patients. Isolated renal MM is an uncommon presentation that has been documented as a life-threatening condition in immunocompetent patients due to its poor prognosis. Here, we present a rare case of isolated renal MM in a 27-year-old male who presented with left flank pain, nausea, and vomiting. Upon further investigation, a renal infarct was discovered, and he underwent a subsequent nephrectomy. A renal biopsy revealed MM. The patient's infection spread, and he ultimately succumbed to his illness. Isolated renal involvement of this pathogen is extremely rare in healthy individuals and has poor outcomes. The ubiquitous nature of MM increases the risk of exposure to humans. Comorbidities such as coronavirus disease 2019 and immunosuppressive states are risk factors for the deleterious outcomes of MM. It is unusual for an immunocompetent patient with no underlying conditions to die despite early diagnosis and prompt treatment. This example calls attention to the unpredictable clinical presentation of isolated renal MM. Our case highlights MM as a differential diagnosis in patients with unilateral flank pain and identifies the importance of a prompt clinical diagnosis and treatment due to the rapid progression and poor health outcomes associated with MM infection.