Atrial fibrillation and tumor emboli as manifestations of metastatic leiomyosarcoma to the heart and lung

Leiomyosarcoma is a malignant tumor of the smooth muscle that rarely occurs in the gastrointestinal tract. High-grade leiomyosarcomas of the rectosigm oid usually metastasize to the liver and lungs. Although it is unusual, met astases to the heart have been reported. When this occurs, the metastatic t umor usually seeds in the right atrium and pulmonary artery. We report on a nd discuss a patient who had atrial fibrillation, peripheral emboli, and th rombocytopenia resulting from a low-grade rectosigmoid leiomyosarcoma metas tatic to the pulmonary vein and left atrium. Atrial fibrillation is not a c ommon manifestation of malignant neoplasms that have spread to the heart. S urgical removal of the tumor terminated the arrhythmia and thrombocytopenia .