Cerebral convexity arachnoid cysts: A focused systematic review with defining characteristics

Arachnoid cysts are non-neoplastic accumulations of cerebrospinal fluid formed within partitioned layers of the arachnoid mater. They represent about 1% of all intracranial masses in humans. Most arachnoid cysts present in the middle cranial fossa, but few occur along the cerebral convexity. Gross imaging of cerebral convexity arachnoid cysts (CCACs) is extremely scarce. The purpose of this study is to conduct a focused systematic review of CCACs and report their defining clinical characteristics. A systematic literature review was conducted to compile and summarize primary sources of anatomical and clinical information about CCACs. A large CCAC was discovered and dissected in a human cadaver. The CCAC was photographed in situ, and its impacts on contiguous gyri and sulci were documented and presented as a representative example of a CCAC. CCAC formation is attributed to congenital (primary) or trauma-related (secondary) etiologies. While they are often asymptomatic, CCAC location and size can influence symptomology. The anticipated increase in intracranial pressure can elicit mild (e.g., headache) to severe (e.g., seizure, hydrocephalus) sequelae. The present study exhibits a remarkably large CCAC that developed within the left central sulcus, displacing the precentral and postcentral gyri. The central sulcus artery and vein were present and appeared unaffected. Management of CCACs can range from close observation with no intervention in asymptomatic cases to surgical intervention. Typical surgical options include microsurgical fenestration via craniotomy, neuroendoscopic fenestration, and various forms of shunting. The efficacy of one surgical approach over another remains highly debated. As CCACs are mostly diagnosed with CT and/or MRI, gross imaging of CCACs is extremely rare. This study provides clinical anatomists, neurologists, and neurosurgeons with visual insight and perspective into the physical and clinical characteristics of CCACs. • Focused systematic review of clinical characteristics of cerebral convexity arachnoid cysts. • Gross cadaveric imaging of a large cerebral convexity arachnoid cyst. • Formal definition of cerebral convexity.