Rapidly Progressive Mucormycosis Presenting as Giant Cell Arteritis as a First Presentation of Diabetes in a Woman With Diabetic Ketoacidosis: A Case Report and Review of the Literature.

Background: Disseminated mucormycosis is a rare, angioinvasive fungal infection predominantly affecting immunocompromised individuals, especially those with poorly controlled diabetes. Case Presentation: A 57-year-old Palestinian woman presented with sudden unilateral blindness, ophthalmoplegia, facial numbness, and ptosis, with hyperglycemia. Early brain MRI/MRA/MRV findings were normal, suggesting that giant cell arteritis, or other autoimmune vasculitis, was suspected; thus, IV steroids were administered. Subsequently, her condition progressed to bilateral fixed pupils, complete ophthalmoplegia, and palatal black necrosis. Subsequent imaging and sinus biopsy confirmed disseminated mucormycosis. Treatment included intravenous Amphotericin B, anticoagulation, functional endoscopic sinus surgery, and later left eye enucleation. Despite maximal therapy, she developed a large hemorrhagic venous infarction and ultimately died. Conclusions: Mucormycosis can initially mimic autoimmune or vascular neuro-ophthalmic disease and may present with normal imaging. In acute vision loss with hyperglycemia, maintaining early suspicion and avoiding corticosteroids until fungal infection is excluded are essential to prevent rapid, fatal progression.