2025 Volume 61 Issue 1 Pages 169-173
A 36-week pregnant woman was referred to our hospital due to a fetal intrathoracic cyst. Fetal ultrasonography and MRI revealed a 3-cm diameter simple cyst in the mid or posterior mediastinum of the right thoracic cavity, compressing the lung from outside. There was no continuity with other thoracic organs, and there was no obvious blood flow in the relatively thick cyst wall. Most of its content was uniformly hypoechoic. We suspected a foregut duplication cyst from these findings. After birth at 38-week, the newborn required no resuscitation immediately but began to show respiratory disorder on day 6. CT scan revealed that the cyst enlarged slightly and compressed the right main bronchus. An open chest surgery was performed and removed the cyst on day 11. The pathological diagnosis was a gastric duplication cyst. Gastric duplication cyst is one of the enteric duplication cysts, and intra-thoracic solitary type is rare. When an intrathoracic cyst is detected prenatally, it is important to narrow down the diagnosis based on the location and characteristics of the cyst for appropriate management after birth. Evaluation of positional relationship between cyst and bronchus may be useful to estimate risk for postpartum respiratory disorder.
