Benign Structures Mimicking Right Atrial Masses on Prenatal Ultrasound

Area of Science:

• Cardiology
• Fetal Medicine
• Diagnostic Imaging

Background:

• Advances in prenatal ultrasound imaging increase the detection of fetal cardiac anomalies.
• Right atrial masses identified prenatally can raise concerns for cardiac tumors, necessitating further investigation.
• Differentiating benign anatomical variations from neoplastic lesions is critical in fetal cardiology.

Observation:

• Two cases are presented where pregnant women were referred for fetal echocardiography due to suspected right atrial masses on prenatal ultrasound.
• Initial suspicion in both cases was tuberous sclerosis, a condition associated with cardiac rhabdomyomas.
• The identified structures were ultimately diagnosed as a prominent crista terminalis and a prominent Chiari network.

Findings:

• The first case involved a prominent crista terminalis, a normal anatomical structure within the right atrium.
• The second case demonstrated a prominent Chiari network, another benign finding in the right atrium.
• Postnatal echocardiography (ECHO) confirmed the benign nature and anatomical characteristics of both identified structures.

Implications:

• Accurate differentiation between benign right atrial structures and cardiac tumors is essential for appropriate prenatal counseling and management.
• Echocardiographic features, including location and echogenicity relative to surrounding atrial tissue, aid in distinguishing these entities.
• Recognizing common benign structures can prevent unnecessary interventions and reduce parental anxiety associated with suspected fetal cardiac tumors.