SAT-632 Rhinocerebral Mucormycosis in New-Onset Type 1 Diabetes: A Diagnostic Challenge

Abstract Disclosure: A. Razzeto: None. S. Barreiro Sacco: None. M. Zamin: None. V. Viviana: None. M. Aoun: None. R.T. Varghese: None. Introduction: Rhinocerebral mucormycosis, a rare, life-threatening fungal infection, often affects immunocompromised individuals, especially those with poorly controlled diabetes. Early diagnosis is vital, but its presentation can be misleading. This case highlights diagnostic and management challenges in a new-onset type 1 diabetic. Case Presentation: A 46-year-old male with a history of alcohol abuse and newly diagnosed type 1 diabetes (HbA1c 12.9%, C-peptide of 0.6 ng/mL with glucose of 337 mg/dL, GAD65 antibody positive) presented from another institution with recurrent Diabetic Ketoacidosis (DKA), altered mental status, rhinorrhea, anosmia and left periorbital swelling. He had a prior DKA admission complicated by Bell's palsy and sinus/mastoid disease on MRI treated with steroids. Exam revealed a febrile, tachycardic patient with left periorbital swelling and redness. Labs confirmed DKA (glucose 604, pH 7.2, bicarb <5, AG 44), leukocytosis, AKI, hyponatremia and prompted immediate insulin infusion. Neuroimaging revealed an air-filled right frontal lobe lesion. Given his presentation, empiric treatment for mucormycosis began with amphotericin B and broad-spectrum antibiotics. Patient underwent a brain abscess drainage and cultures grew S. aureus, E. faecalis, and S. anginosus. However, the patient worsened with restricted left eye movement, periorbital purulence, and hard palate erosion. Repeat imaging showed invasive fungal sinusitis with intracranial extension, orbital/retroantral abscesses, cavernous sinus thrombophlebitis, bifrontal abscesses, otomastoiditis, cavernous sinus thrombophlebitis and meningoencephalitis. Further surgery included bifrontal craniotomy, sinus debridement, and orbitotomy. Histopathology finally confirmed mucormycosis (broad, non-septate hyphae) with bacterial superinfection (MSSA, E. faecalis). Treatment intensified with liposomal amphotericin B, posaconazole, and targeted antibiotics (vancomycin and zosyn) leading to clinical improvement. Conclusion: This case highlights the critical importance of considering rhinocerebral mucormycosis in poorly controlled diabetics (especially type 1) with sinonasal/neurological symptoms. Conditions that can mask the diagnosis, including bacterial co-infections, DKA, electrolyte abnormalities can delay diagnosis. Prompt, aggressive antifungal treatment and surgical debridement are crucial, given the high mortality (up to 50%). Autoantibody testing can help diagnose type 1 diabetes and initiate timely insulin treatment, potentially preventing these devastating complications. Vigilance is vital in high-risk groups. Presentation: Saturday, July 12, 2025