Arachnoid cyst with spontaneous intracystic hemorrhage and associated chronic subdural hematoma: A case report

INTRODUCTION AND IMPORTANCE: Spontaneous hemorrhage of the arachnoid cyst was rare, especially associated with chronic subdural hematoma (CSDH). In this paper, we reported successful surgical management of arachnoid cyst with spontaneous hemorrhage and associated subdural hematoma. CASE PRESENTATION: A 33-year-old female with no medical history was presented with a headache for one month prior to admission. Head computed tomography and magnetic resonance imaging showed a left hypodense middle cranial fossa arachnoid cyst and ipsilateral CSDH. The multiple-slice computed tomography with contrast showed no vascular abnormality. The patient was indicated for surgical hematoma evacuation, membranectomy, and fenestration of the arachnoid cyst. At the one postoperative month, the computed tomography showed a middle fossa arachnoid cyst with no hemorrhage. Until a postoperative year, the patient had no headache and no neurological deficits. She returned to daily activities and her work. CLINICAL DISCUSSION: This event's pathogenesis was thought of as a result of tearing of the outer wall of an arachnoid cyst. The most common cause was mild head trauma; however, spontaneous rupture of the cyst wall also occurred. Surgery was the most common and effective treatment. Evacuation of CSDH was mandatory, but the strategies treatment for arachnoid cysts varied. Surgical options for arachnoid cyst included endoscopic/microsurgical fenestration, membranectomy, and even the cysto-peritoneal shunting. CONCLUSION: Arachnoid cyst with spontaneous intracystic hemorrhage accompanying CSDH was an uncommon condition. Surgery was the most common and effective treatment. Besides evacuation of CSDH, endoscopic/microsurgical fenestration or membranectomy was recommended to prevent the recurrence.