Etiology and outcome of prenatally detected paracardial cystic lesions: a case series and review of the literature.

OBJECTIVES

Isolated paracardial cysts, defined as cystic structures adjacent to or originating from the heart, are rare and etiologically heterogeneous congenital abnormalities. The purpose of this study was to review our experience with prenatally diagnosed isolated cysts.

METHODS

We reviewed retrospectively the medical charts and ultrasound records of all cases with an antenatal diagnosis of paracardial cyst at our institution between 2001 and 2006. Where applicable, the diagnosis was further substantiated by other imaging modalities and pathology.

RESULTS

The cysts in six fetuses were diagnosed at a median gestation of 20 (range, 19-38) weeks. Three of these fetuses presented with a fluid-filled cyst attached to or within the pericardial space (pericardial cysts), which resolved spontaneously by the time of delivery. In contrast, the cysts did not change in size or shape in the remaining three fetuses. Postnatal examination of the persistent cysts revealed three different etiologies: (1) a microcystic lymphangioma, located in the anterior mediastinum; (2) an isolated neurenteric cyst; and (3) a single bronchogenic cyst, both within the posterior mediastinum. The lymphangioma and neurenteric cyst were removed surgically after birth.

CONCLUSIONS

Fetal echocardiography enables early detection of paracardial cyst. Pericardial cysts disappeared spontaneously during the course of gestation without signs of fetal cardiac compromise, suggesting a benign prognosis. Imaging by magnetic resonance and computerized tomography were particularly useful to clarify the etiology, structure and extent of those cysts that had not resolved by the time of birth. Published by John Wiley & Sons, Ltd.