Intraoperative ultrasound-assisted endoscopic endonasal transclival marsupialization of an ectopic retrosellar Rathke's cleft cyst: A rare case illustration and systematic review of the literature.

Not every Rathke's cleft cyst (RCC) is confined within the sella between the posterior and anterior lobes of the pituitary gland. Intracranial ectopic RCCs are extremely rare, with only seven cases reported in the literature. In this study, the authors presented a rare case of a symptomatic ectopic retrosellar RCC posterior to the pituitary gland, causing extensive clival erosion. The surgical nuances of the wide marsupialization of the cyst through intraoperative ultrasound-assisted endoscopic endonasal transclival approach are described, and a systematic literature review of intracranial ectopic RCCs is conducted.