Myxoid Pleomorphic Liposarcoma Imitating Recurrent Traumatic Hemopericardium.

BACKGROUND

Primary pericardial malignancies are rare, and myxoid tumors may mimic hemorrhagic pericardial effusions on imaging, leading to diagnostic delay.

CASE SUMMARY: A 56-year-old man presented with pleuritic chest pain and was diagnosed with acute pericarditis and a presumed traumatic hemorrhagic pericardial effusion. Despite anti-inflammatory therapy and pericardiocentesis yielding bloody, lymphocyte-predominant fluid with negative cytology, he experienced rapid clinical deterioration. Repeat imaging revealed an encasing pericardial mass causing severe left atrial compression and functional mitral stenosis. Emergent surgical exploration identified a large solid pericardial tumor. Histopathology confirmed primary myxoid pleomorphic liposarcoma. The patient underwent surgical resection followed by adjuvant chemotherapy and radiotherapy.

DISCUSSION: This case highlights the myxoid tumor's masquerade as a hemorrhagic effusion, the limitations of pericardial fluid cytology for sarcoma, and the hemodynamic consequences of external cardiac compression.

TAKE-HOME MESSAGE: Persistent or recurrent bloody pericardial effusions with atypical imaging features warrant suspicion for malignancy despite negative cytology.