Spontaneous rupture of middle fossa arachnoid cysts: surgical series from a single center pediatric hospital and literature review

Purpose: Arachnoid cysts may present with symptoms deriving from cyst rupture, usually causing intracystic hemorrhage and subdural hematoma or hygroma. Rupture is usually caused by minor trauma, spontaneous rupture is an exceptional event, and 57 cases have been described in literature. We here present and discuss the largest series of spontaneously ruptured middle fossa arachnoid cysts in order to investigate clinical presentation and best treatment available. Methods: We report a retrospective series of 17 pediatric patients surgically treated for middle fossa arachnoid cyst with signs of cyst rupture without a history of trauma in the previous 90 days. We describe clinical presentation, treatment, and outcome at follow-up discussing our results with a literature review including all reported cases of spontaneous rupture of middle fossa arachnoid cysts. Results: In our experience patients most frequently presented with subdural hygroma, in literature, a chronic hematoma was most frequently reported. Headache is the most reported symptom at presentation. Neurological deficits and consciousness alterations are rare. Surgical treatment may resolve brain compression only or reduce rupture recurrence risk. Conservative treatment has also been proposed. Different treatments are reported and discussed focusing on indications, contraindications, risks, and expected benefits. Conclusion: We propose, when safely possible, microsurgical cyst fenestration in skull base cisterns as the treatment of choice for these patients as long as it addresses both immediate decompression and risk of rupture recurrence. We report good outcomes and low incidence of complications from our series with a mean postoperative follow-up of 30 months.