RA tumors are needed to be differentiated from anatomic variants.
myxoma appears as a globular or spherical mass with a friable surface and heterogeneous internal echogenicity.
Myxomas typically arise from the interatrial septum around the fossa ovalis.
Metastatic tumors including hepatoma, RCC, & sarcoma from pelvic organs reaching RA through IVC can be seen in echo.
Careful tracing the origin of mass will give a clue for differential diagnosis from benign anatomic variants.
Atrial Septum Variants: Atrial Septal Aneurysm ■ Atrial septal aneurysm (ASA) is found in 1% of adults at autopsy. ■ An excursion of > 10 mm beyond the plane of interatrial septum is recognized as ASA, although such cut-off value is arbitrary. ASA may involve only the region of fossa ovalis, or the entire interatrial septum. Frequent a/w ASD, PFO, MVP, Marfan syndrome suggests that ASA is congenital malformation with genetic background. Lipomatous Hypertrophy of the Atrial Septum ■ lipomatous hypertrophy refers the condition of prominent thickening of interatrial septum, usually > 2 cm, caused by excessive fatty infiltration. ■ it actually represents the fat-filled extracardiac spaces which is not encapsulated unlike true lipoma. ■ Echocardiographic diagnosis is made when a marked atrial septal thickening > 15-20 mm in the absence of any other explanation for the abnormal thickening. ■ Patients with lipomatous hypertrophy tend to have heavy pericardial and periaortic fat infiltration. ■ Lesser degree of atrial septal thickening can occur in amyloidosis, tumors, and a surgical patch covering repaired atrial septal defect. It is generally benign condition & asymptomatic ■However, the blood flow obstruction of SVC and coronary sinus, intra-atrial conduction disturbance, supraventricular arrhythmia, syncope, and even sudden death had been reported.
■ A dilated coronary sinus can mimic an LA mass in the parasternal long axis view, as can a prominent descending aorta from the apical view.
A left arm injection of agitated saline will define a persistent left superior vena cava draining into the coronary sinus, which is the m.c structural anomaly a/w dilatation of coronary sinus.
Ridge between the LA appendage (LAA) and left superior pulmonary vein (LSPV). TEE views of this normal ridge in two different patients are shown. Sometimes this ridge is evident on TTE parasternal short-axis or apical two-chamber views.
