Sphenoid fungal rhinosinusitis across the disease spectrum: a case series of non-invasive fungal ball and fatal acute invasive fungal rhinosinusitis.

INTRODUCTION: Sphenoid fungal rhinosinusitis is an uncommon but clinically important entity ranging from non-invasive fungal ball to rapidly fatal acute invasive fungal rhinosinusitis. CASE PRESENTATION: We report two contrasting cases of sphenoid fungal disease. The first was a 28-year-old immunocompetent woman with chronic unilateral refractory headache caused by an isolated sphenoid fungal ball, which was successfully treated with endoscopic sphenoidotomy and clearance. The second was a 49-year-old man with diabetes mellitus who presented with orbital involvement, cavernous sinus thrombosis, and fungal encephalitis due to an invasive Rhizopus infection, despite urgent debridement and systemic amphotericin B, with a fatal outcome. DISCUSSION: These cases illustrate how sphenoid fungal disease may present either as an isolated refractory headache in an otherwise healthy patient or as a fulminant invasive infection in a high-risk host. Early imaging, endoscopic assessment, and timely differentiation between non-invasive and invasive disease are essential because management and prognosis differ markedly. CONCLUSION: The paired presentation highlights key red flags for early diagnosis and emphasizes the need for prompt multidisciplinary management, especially in diabetic or immunocompromised patients.