[Cyst puncture and injection of contrast medium for diagnosis and treatment of pericardial cyst].

We present two cases of pericardial cyst diagnosed by cyst puncture and the injection of contrast medium. The first patient was a 48-year-old man. He was admitted for the evaluation of an abnormal chest X-ray which demonstrated a mass lesion inseparable from the right heart border. CT scan confirmed the mass in the anterior cardiophrenic angle. The mass was quite homogeneous, with an attenuation value of -0.3 HU. Under CT guidance a 21-G needle was inserted into the cyst and 3 ml of clear fluid was obtained, and then contrast medium was injected. A thin smooth walled cyst was outlined by the CT scan. A presumptive diagnosis of pericardial cyst was made. Surgery was performed and the diagnosis was confirmed. The second patient was a 24-year-old woman. An abnormal shadow was noted at annual check up. CT scan confirmed the mass in the anterior cardiophrenic angle. The mass was quite homogeneous, with an attenuation value of +10.4 HY. We made the diagnosis of pericardial cyst by cyst puncture and injection of contrast medium. The CT scan after three months showed no recurrence of the pericardial cyst. We consider that pericardial cyst can be diagnosed clearly by cyst puncture and the injection of contrast medium, and only percutaneous aspiration of the cyst fluid may be sufficient for the treatment.