Prenatal tomography ultrasound imaging diagnosis of fetal pyriform sinus cysts (third or fourth branchial cleft cyst): A case report

This case report describes a fetal piriform sinus cyst identified via tomographic ultrasound imaging and discusses its prenatal sonographic characteristics. We employed the tomographic ultrasound imaging function of the GE Voluson Ultrasound E10 to visualize multilevel transverse sections of the cyst. Specifically, we propose for the first time that the cross‐sectional shape of a piriform sinus cyst composed of aryepiglottic folds approximates a triangle. This special shape facilitates the precise localization of the piriform sinus, providing valuable insights for timely diagnosis and appropriate postnatal management.