2025 Volume 61 Issue 2 Pages 324-328
【Introduction】Advancements in fetal ultrasonography have increased the detection of pyriform sinus fistula（PSF）as a fetal cervical cyst. Since PSF often presents with respiratory distress or infection, early diagnosis is crucial. However, right-sided cases are rare and frequently lead to delayed diagnosis.
【Case 1】A fetal cervical cyst was detected on the right side during the prenatal period. Postnatal ultrasonography revealed an irregularly shaped, simple cyst in the right neck. On the first day of life, air was observed within the cyst following the initiation of oral feeding. By day three, debris appeared, and by day five, signs of cyst infection were noted. Surgical excision of the cyst was performed on day eight.
【Case 2】A fetal cervical cyst was detected on the right side during the prenatal period. Postnatal ultrasonography revealed an irregularly shaped, simple cyst containing air on the right side of the neck. The air content increased following oral feeding. By day two, debris appeared, and by day five, signs of cyst infection were noted. Surgical excision of the cyst was performed on day seven.
【Discussion】PSF exhibits characteristic ultrasonographic findings, with the sequential appearance of air and debris within a previously simple cyst. Frequent ultrasonographic evaluation is essential for early diagnosis, and PSF should be considered in the differential diagnosis, even for right-sided cervical cysts.
