Congenital conjunctival cyst detected by prenatal ultrasound.

Purpose: The purpose of this manuscript is to report a rare case of an orbital cyst detected intrauterine with sonography.

Observation: A 23-year-old female presented for routine prenatal monitoring when an orbital cyst was detected with a transabdominal ultrasound. Uncomplicated cesarean section was performed at 38 weeks gestation with proptosis of the left globe being noted on ophthalmic examination of the newborn. Magnetic resonance imaging was conducted which demonstrated a cystic mass suspicious for lymphatic malformation. Surgical intervention was performed shortly after birth with pathological results demonstrating non-keratinizing squamous epithelium consistent with conjunctivoid variant of dermoid cyst. Post-operative examination demonstrated significant improvement of the exophthalmos with minimal lagophthalmos.

Conclusions: Congenital orbital cysts are a rare phenomenon with only a handful of cases being detected during the fetal period. We recommend physicians include this rare variant of dermoid cysts in their differential diagnosis for orbital lesions that can cause proptosis in the fetal period.