Spontaneous Shrinkage of a Suprasellar Arachnoid Cyst Diagnosed with Prenatal Sonography and Fetal Magnetic Resonance Imaging: Case Report and Review of the Literature.

Arachnoid cysts (AC's) are congenital anomalies that occur within the cerebrospinal fluid (CSF) cisterns and major cerebral fissures. Suprasellar AC's comprise 5-12.5% of all the lesions. Despite being commonly reported, their etiology and pathogenesis still remain unclear. In this report, we presented an unusual case of spontaneous shrinkage of a suprasellar AC that had been incidentally diagnosed during a routine prenatal sonographic examination. To our knowledge, only three cases of spontaneous shrinkage of suprasellar AC have been reported in the literature. In detail of the manuscript, fetal and postnatal radiological images were presented and the possible mechanisms were discussed with a review of the literature.