Incidental Middle Cranial Fossa Arachnoid Cyst Complicated by Spontaneous Intracystic Hemorrhage and Contralateral Subdural Hematoma: A Rare Case Report

Arachnoid cyst is a benign lesion characterized by a collection of cerebrospinal fluid within the arachnoid membrane layers, often discovered incidentally. Cranial arachnoid cyst associated with subdural hematoma has been described; however, AC complicated with spontaneous intracystic hemorrhage and contralateral SDH is a very rare presentation. The authors describe a unique presentation of a 43-year-old female with an incidentally discovered middle fossa arachnoid cyst, further complicated by spontaneous intracystic hemorrhage and a contralateral subdural hematoma. The patient presented with non-specific signs of intracranial hypertension, necessitating urgent surgical intervention for hematoma evacuation. The occurrence of an incidental middle cranial fossa arachnoid cyst complicated by spontaneous intra-cyst hemorrhage and contralateral subdural hematoma, resulting in a life-threatening condition, represents an exceedingly rare clinical presentation. Prompt surgical evacuation of the hematoma, without direct intervention on the asymptomatic arachnoid cyst, leads to improved patient outcomes. In the absence of clinical manifestations associated with the arachnoid cyst, a non-operative management approach, involving patient counseling and regular follow-up, may be considered a viable option.