Hemorrhagic complication of arachnoid cyst: A case report and literature review

Abstract

Arachnoid cysts (ACs) are congenital malformations that can form anywhere in the subarachnoid space along the cerebrospinal axis. While intracystic hemorrhage and subdural hematoma (SDH) are rare, they can be urgent complications that may require emergency craniotomy. This report aims to present a case of an AC complicated by intracystic hemorrhage and SDH. A 63-year-old man presented after a fall, reporting a mild headache, right-sided weakness, confusion, speech difficulties, and gait ataxia. Brain magnetic resonance imaging (MRI) revealed an acute or early subacute SDH. A cystic structure measuring 9 × 6 × 5 cm and showing hemorrhagic characteristics was identified deep within the left SDH. The patient underwent a left-sided craniotomy to evacuate the SDH and remove all surrounding membranes. Additionally, an intracystic hematoma was evacuated, and the cyst wall was fenestrated. The patient remained stable during the follow-up. Over the past decade, a brief literature review on AC complicated by intracystic hemorrhage and SDH identified 9 case reports encompassing ten cases. Patient ages ranged from 6 to 47 years, with only 2 (20%) female patients. Headaches were the most frequent symptom, present in all patients, while eight patients (80%) had no history of head trauma. Only two cases (10%) were treated conservatively. In conclusion, individuals with AC are vulnerable to developing intracystic hemorrhage and SDH, either spontaneously or post-trauma. Open craniotomy combined with cyst fenestration can lead to preferred outcomes in treating this condition.

Keywords: Arachnoid cyst; Craniotomy; Cyst fenestration; Intracystic hemorrhage; Subdural hematoma.

Graphical abstract

Fig. 1

The brain MRI images demonstrate (A) A T2-weighted coronal section and (B) A T1-weighted axial section, revealing an intermediate signal collection on the left side comprising 2 components with varying gray levels. The “arrowhead” highlights the subdural collection, and the “ arrow” marks the cystic collection extending into the suprasellar region.

Fig. 2

(A) The brain MRI susceptibility weighted imaging sequence axial section reveals a linear blooming signal, indicated by the “arrow,” which suggests hemorrhagic content. (B) The T1-weighted axial section with IV contrast displays dura enhancement, marked by the “arrowhead,” surrounding both the subdural collection and the cystic lesion.

Fig. 3

The intraoperative images demonstrate (A) A wide craniotomy with exposed dura, showing a dark appearance of the underlying hematoma. (B) A cruciate durotomy revealing a thick-walled SDH. (C) Complete removal of the SDH, exposing a clear cavity of the AC and the cortical surface of the brain, extending to the skull base following excision of the AC wall.