An atypical visual presentation in a setting of a critically thinned optic nerve compressed between a Rathke's cleft cyst and anterior cerebral artery: illustrative case.

Background: A superior temporal visual field defect is the first sign of a chiasmal disorder by a suprasellar mass lesion. Some lesions may present with atypical visual deficits.

Observations: The authors present the case of a 71-year-old woman who presented with inferior temporal hemianopia of the left eye in the setting of a Rathke's cleft cyst (RCC). During transsphenoidal surgery, they found the optic nerve was compressed by the anterior cerebral artery (ACA) and appeared translucent. Preoperative MRI revealed that the left optic nerve was compressed between the ACA and RCC, corresponding to surgical findings. Postoperative imaging showed optic nerve thinning and notching on its surface.

Lessons: In patients with visual field impairment by sellar mass lesion, attention should be paid not only to upward compression by the mass lesion but also to downward compression by the ACA. https://thejns.org/doi/10.3171/CASE25334.