Rationale: Orbital apex syndrome is a complex clinical disorder featuring a collection of cranial nerve deficits characterized by impairment of the extraocular muscles, the ophthalmic branch of the trigeminal nerve, and even the optic nerve. Sino-orbital aspergillosis is rare but aggressive infection. Surgical resection accompanied by antifungal medication is advised currently.
Patient concerns: We report a 61-year-old woman diagnosed as aspergilloma presenting with the characteristic manifestations and imaging features of orbital apex syndrome.
Diagnoses: Paranasal sinus tumor was misdiagnosed initially according to magnetic resonance imaging of the orbit. Finally aspergilloma was diagnosed by pathologic report.
Interventions: The anti-fungal medication, voriconazole, was administered immediately. Surgical excision was also done due to the poor response to medical treatment.
Outcomes: Postoperative follow-up showed no recurrence of aspergillosis but the vision was lost permanently.
Lessons: Invasive sino-orbital aspergillosis as an aggressive disease with highly invasive patterns and it may be misdiagnosed as tumors. To achieve better prognosis and survival, clinicians should be aware of this distinct manifestation.