What happened, in summary

A 59-year-old woman with recurrent small cell lung cancer had previously received chemotherapy and radiation. She later developed progressively worsening pain in her left upper extremity, prompting further evaluation. Cardiac imaging identified an unusual intracardiac finding: an irregular echogenic mass measuring 37 mm by 26 mm, partially attached to the posterior atrial aspect of the tricuspid valve. The tricuspid valve sits between the right atrium and right ventricle, so a malignant mass in this location can create concern for obstruction, embolic events, or worsening cardiopulmonary symptoms in a patient already being treated for recurrent cancer. The care team proceeded with mechanical aspiration to remove the mass and obtain tissue for diagnosis. The procedure was successful, and biopsy demonstrated malignant myoepithelial disease. The key clinical event was therefore a recurrent small cell lung cancer history complicated by a malignant right-sided heart mass involving the tricuspid-valve region. Her presenting symptom was left arm pain rather than a new respiratory complaint, showing how recurrent thoracic cancer can sometimes lead to urgent cardiovascular evaluation. The cardiac mass was large enough to be clearly measured on imaging and was attached to a moving valve structure, which made tissue diagnosis and removal clinically important. After aspiration, the malignant nature of the mass was confirmed by biopsy. Her prior oncologic treatment included chemotherapy and radiation, while the immediate documented outcome was successful removal of the intracardiac mass and confirmation of the diagnosis. This case emphasizes symptom-driven detection of a cardiac tumor deposit and successful catheter-based management of that immediate threat.