Unexplained Massive Pericardial Effusion Revealing Intrapericardial Lymphangioma

Intrapericardial lymphangioma is a rare benign lymphatic tumor that may present with nonspecific findings and unexplained pericardial effusion, posing a diagnostic challenge.

A 33-year-old woman presented with dyspnea and a large pericardial effusion without tamponade. Multimodality imaging revealed multiloculated pericardial and mediastinal lesions, but diagnosis remained uncertain. Because of inconclusive findings, surgical biopsy was performed. Histopathology and immunohistochemistry (ETS-related gene, CD31, and D2-40) confirmed intrapericardial lymphangioma. The patient underwent partial pericardiectomy with a favorable outcome.

Noninvasive modalities may be insufficient to determine the etiology of pericardial effusion with associated masses. Tissue diagnosis is often required.

Early tissue diagnosis should be considered in unexplained pericardial effusion when imaging is inconclusive.