You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
a 60-year - old woman visited daegu catholic university medical center due to periumbillical pain lasting several days .
the patient had no medical history except a benign ovarian tumor which she had under gone surgery 13 years earlier . according to physical examination findings , the sound of a regular heart beat and clear breathing were observed .
the blood pressure was 108/69 mmhg , pulse 81 beats per minute , respiratory rate 20 breaths per minute , and body temperature 36.5. on laboratory test , only the cholesterol was high at 205 mg / dl .
old pulmonary tuberculosis was observed through a simple chest x - ray . on a computed tomography ( ct )
scan of the abdomen , a lesion suspected being a mass on the right atrium was found ( fig .
1 ) . on trans - thoracic and trans - esophageal echocardiograms , a 2.653.06 cm mobile cystic mass was visible on the right atrium and some small calcified masses were also seen inside ( fig .
normal cardiac function was observed , and no abnormal observations were found in cardiac motility or the heart valves .
positron emission tomography - ct was performed due to her gynecologic history , but there was no evidence of malignancy and the ca-125 was within normal range .
after median sternotomy , an arterial cannula was inserted into the ascending aorta and , a venous cannula into the superior and inferior vena cava .
we also started extracorporeal circulation , and decreased the central temperature to 28. cardioplegia was induced by infusing retrograde cardioplegic solution into the coronary sinus , an incision was made in the right atrium , and a 3 cm cystic mass was identified on the lower margin of the limbus fossa ovalis , which had been connected by a stalk .
the cystic mass was completely removed , and three 0.5 cm calcified masses and old blood without clotting were found in the cyst ( fig .
chiari 's network is a congenital disease characterized by a remnant of the right valve of the sinus venosus .
it was first described in 1897 by hans chiari , who described 11 cases in which the valve of the inferior vena cava , the eustachian valve , represented by networks with attachments to the superior vena cava and to the tubercle of lower . in normal embryology , the right valve of the sinus venosus
is regressed , while the thebesian and eustachian valves are remain at 15 weeks of gestational age .
chiari 's networks are present in 1.5% to 4% of the population , and they rarely have clinical significance [ 2 - 4 ] .
some reports have described the network as highly mobile , with an oscillating or whiplike motion pattern during each cardiac cycle .
the close relationship between chiari 's networks and patent foramen ovales ( pfos ) has been well documented . according to schneider et al .
, pfo was detected in 83% of patients with chiari 's networks compared with 28% of controls .
however , in patients with chiari 's network , a pfo was significantly more common in arterial embolic events .
they also found that right - to - left shunting of a pfo was significantly more common in patients with chiari 's network than in control patients .
for this reason , pfos may become a source of cerebral and peripheral arterial emboli , although a right atrial thrombus is usually asymptomatic in chiari 's network .
.   identified atrial aneurysms in 7 out of 29 patients with chiari 's networks , who were associated with a pfo . in the same context , among the patients with atrial aneurysms , 21%
there are reports of chiari 's networks acting as a physical barrier of right - sided catheters and pacemakers .
there are also rare reports of chiari 's network associated with valvular endocarditis . the diagnosis of chiari 's network is usually made incidentally .
the echocardiographic finding of chiari 's network is a mobile curvilinear structure on the right atrium .
ct and magnetic resonance imaging also differentiate chiari 's network from other cardiac masses . in our case ,
the patient was not found to have pfo , atrial thrombus , or atrial aneurysm .
we presumed that the right atrial mass was a teratoma as her history of ovarian tumor and echocardiographic findings were cystic and calcified lesions . on pathologic study
the mass was confirmed as chiari 's network . as cystic form of chiari 's network
have not been reported before , it is the first report of cystic form of chiari 's network .
chiari 's networks are present in 1.5% to 4% of the population . 
 they are a congenital disease characterized by a remnant of the right valve of sinus venosus and rarely have clinical significance . 
 chiari 's network , as the name implies , has network - like shape , but there are other forms of appearance . we have experienced a case of a 60-year - old woman who had a cystic mass on the right atrium . 
 surgical treatment was performed forthe mass removal and differential diagnosis of the mass . 
 there was no evidence of other tumor , but chiari 's network . 
 as cystic form of chiari 's network have not been reported before , it is the first report of cystic form of chiari 's network .