Fenestration of a Symptomatic Intrasellar Arachnoid Cyst through an Eyelid Incision

Fig. 1

Intracranial arachnoid cysts (AC) are benign lesions, forming ~1% of all intracranial space-occupying lesions. Intrasellar arachnoid cysts (IAC) constitute ~3% of all intracranial arachnoid cysts. Two pathophysiologic mechanisms have been proposed for the development of IAC. Both hypotheses rely on the presence of anatomic variation of the diaphragma sellae that permits herniation of the basal arachnoid layers into the sellar compartment. The first hypothesis proposes that closure of the arachnoid diverticulum due to either meningitis, hemorrhage, or inflammation result in a noncommunicating intrasellar cyst. The second hypothesis suggests that cyst enlargement occur through a ball-valve mechanism. Generally, IACs are asymptomatic and requires no intervention. Surgical treatment indicated for cysts that cause chiasmatic compression, pituitary dysfunction, and/or severe headaches. We present a 63-year-old female with history of hypercalcemia and diabetes insipidus (DI) for 7 years. She presented with headache and blurriness of vision for ~2 years. Her headaches are severe, persistent, aching in nature, and deep bifrontal in location. Neurological exam was normal except for left sided temporal hemianopsia. MRI brain showed intrasellar non enhancing cystic lesion consistent with arachnoid cyst. She underwent a fronto-orbital craniotomy with fenestration of the cyst through an eyelid crease incision. On 6 months follow up her headaches had significantly improved from daily to 2–3 times a month, left visual field deficit improved, and her DI had resolved. Intrasellar arachnoid cysts usually found incidentally. Symptomatic ones require surgical fenestration either through transcranial or transsphenoidal route. Establishing a communication between the cyst and the normal cerebrospinal fluid circulation is the single most important determinant of success.

Fig. 2