A unique atrial primary cardiac lymphoma mimicking myxoma presenting with embolic stroke: a case report.

An immunocompetent 29-year-old male presented with an embolic stroke from an unusual primary cardiac lymphoma. The cardiac lesion consisted of a polypoid, left atrial, mural fibrin thrombus with anaplastic tumor cells lining the surface of the clot. Histologic, immunophenotypic, and molecular characterizations were consistent with a diagnosis of CD30+ large B-cell lymphoma with anaplastic cytology. While tumor emboli from invasive primary cardiac lymphomas have been reported, this noninvasive fibrin thrombus-associated lymphoma appears to be unique and previously unreported.