P1311 A rare case of asymptomatic cyst in interatrial septum longterm observation

Abstract

Abstract Background Incidental findings in echocardiography performed from other indications are not always able to explain the patient condition as well as the observed pathology. However, review of literature, helps to find the most possible explanation. We present a case study of a patient with our proposal of possible diagnosis. Case report 28-year old female with hypothyroidism and no other concomitant diseases presented with easy fatigue. Exercise stress test was clinically and ECG negative with 12,8 METs. Transthoracic echocardiography showed normal size of heart structures with preserved systolic and diastolic function of both left and right chamber. The only abnormality was a cystic structure of 44x31x34 cm in interatrial septum which was protruding to both left and right atrium and was not affecting the blood flow with normal gradients. We did not find any signs of inflammation nor infiltration to the heart walls. There was no flow inside the cyst with the use of colour Doppler. The structure had homogenous echolucency with very thin walls and a septum inside. As we did not find any connection between the cyst and the atriums we considered it as not harmful in terms of a risk of embolization. Patient was hemodynamically stable, there was no history of neurological dysfunctions nor atrioventricular conduction disturbances. Taking into account possible diagnoses for that patient we decided to schedule the patient for follow-ups. Ten years observation period confirmed that that our approach was proper. Serial echocardiographic studies showed no change in the cyst. In this year we performed multimodality imaging with CT and MRI, which showed the same views as echocardiography. Discussion The most possible diagnose for our patient is a bronchogenic cyst, a very rare congenital bronchopulmonary malformation of the foregut that is usually found incidentally with mostly asymptomatic benign course. Also the localization of the cyst confirms that diagnosis. Nevertheless the final diagnosis would be possible only in histopathological study. The differential diagnosis should include a cystic myxoma and echinococcosis. However the structure is not polycystic and seems to have homogenous echolucency. We ruled out the blood cyst because of the lack of typical localization and connection to valves. As long as the patient remains asymptomatic surgical resection remains controversial.