Mount Fuji sign in invasive fungal rhinosinusitis.

We report on a fatal case of invasive fungal rhinosinusitis with after lung transplantation. After endoscopic treatment and adjuvant medical therapy with isavuconazole, caspofungin and an investigational antifungal drug, there was a good clinical response with absence of endoscopic and radiographic disease. However, the patient developed disease recurrence, with signs of intracranial involvement on MRI, for which urgent endoscopic sinus surgery was performed and isavuconazole was restarted. In the days following the surgery, the patient suffered from increasing headache and confusion, with CT scan displaying a Mount Fuji sign (tension pneumocephalus). Best supportive care was provided, but the patient succumbed shortly after. Autopsy demonstrated a perforation at the skull base due to locally invasive fungal infection.Invasive fungal rhinosinusitis is uncommon, mainly occurs in subjects with altered host defence, requires multimodal treatment and has a poor prognosis, with tension pneumocephalus as a rare, life-threatening complication.