Successful Sirolimus Treatment for Recurrent Pericardial Effusion in a Large Cervicomediastinal Provisionally Unclassified Vascular Anomaly: A Case Report.

Provisionally unclassified vascular anomalies (PUVA) are a group of diseases with unique characteristics that make them unclassifiable within vascular tumors or malformations. We describe a PUVA as the cause of recurrent pericardial effusion and its response to sirolimus. A 6-year-old girl was referred with a cervicothoracic vascular anomaly, a violaceous, and irregular lesion in the neck and upper chest, diagnosed as "hemangioma".