Citation Information :
Rosales-Aedo O, Alvarez-de-la-Rosa M, Padilla AI, Troyano JM. Fetal Mediastinal Mass Associated with Arrhythmia: Artifact and Casual Finding in Ultrasound Diagnosis. Donald School J Ultrasound Obstet Gynecol 2018; 12 (4):258-261.
Aim: We aim to report a case of an enlarged fetal thymus causing arrhythmia.
Background: Fetal mediastinal masses may be clinically asymptomatic or cause hemodynamically significant alterations, heart failure, arrhythmias, and sudden cardiac death.
Case description: We present a case of fetal mediastinal mass associated with an arrhythmia. A 29-year-old primigravida, with no previous medical history, was referred to our center due to suspicion of fetal arrhythmia detected in a routine control in week 34. A thymus of hyperplasic characteristics was suspected in the ultrasound evaluation. Pregnancy concluded uneventfully with favorable neonatal outcome.
Conclusion: The fetal thymus is a structure that usually goes unnoticed during the process of prenatal diagnosis, and when it presents alterations in its morphology, can lead to confusion.
Clinical significance: The fetal thymus can be physiologically enlarged and cause fetal arrhythmias without an adverse clinical outcome.
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