Rationale: We report a case of fetal lingual cyst that was diagnosed prenatally using 2-dimensional and 3-dimensional images during routine second trimester screening. To the best of our knowledge, this is the first description of a cystic lesion disappearing before birth.
Patient concerns: A 36-year-old woman at 22 weeks' gestation showed the presence of an oral cystic lesion in routine second trimester ultrasound screening. The lesion measured 18 × 15 × 15 mm.
Interventions: A follow-up ultrasound examination was performed every 4 to 6 weeks.
Outcomes: The cyst disappeared in a follow-up ultrasound examination at 35 and 37 weeks of gestation. A male newborn who weighed 3480 g was delivered with no feeding difficulties. The boy was followed to 6 years after birth. The child had normal growth and development, and there was no recurrence of the cyst.
Lessons: Prenatally diagnosed lingual cysts are uncommon findings that can include many different pathologies with a wide spectrum of severity. Lingual cysts usually have a good prognosis.