LAUSR

A 48-year-old African–American female presented to the Emergency Department with a complaint of chest discomfort and dyspnea. The patient was known to have squamous cell carcinoma of the bladder diagnosed 3 months prior, with invasion into the muscularis propria, staged as T2NxMx. On auscultation, there was a soft systolic murmur. Electrocardiography showed that sinus tachycardia and cardiac biomarkers were within normal limits. CT angiography (CTA) done in the Emergency Room excluded pulmonary emboli. Transthoracic echocardiography revealed normal cardiac function with preserved ejection fraction. However, the right ventricle was enlarged with an echodense round mass in the distal RVOT (arrow, Fig. 1a, b). The mass measured 2.2 × 1.9 cm (Fig. 1c) and was pedunculated with independent motion (see supplemental video) leading to turbulent flow in the RVOT. The rest of the examination was positive only for a small circumferential pericardial effusion. 18FDG PET scanning strongly suggested that this was a metastatic lesion. There was intense 18FDG uptake centered in the RVOT (Fig. 1d) with extension proximally and distally and SUV of 12.8. Unfortunately the patient died 3 months later with confirmed widespread metastatic disease from aggressive carcinoma of the bladder. Metastatic cardiac masses are typically from mediastinal or thoracic primary neoplasms or melanoma [1]. Metastases disseminate to the heart via three main routes: lymphatic, hematogenous, and direct or transvenous. The most frequent carcinomas implicated are breast and lung, with infradiaphragmatic tumors far less common [2]. Malignant melanoma, lymphoma, leukemia, and sarcoma usually spread hematogenously. Extracardiac tumors may also reach the atria and even the chambers of the heart by transvenous extension. To note, intraluminal growth of renal cell carcinoma through the renal vein into the vena cava and right atrium occurs in 1% of these tumors [2, 3]. There are only a handful of cases reported with cardiac metastasis from urothelial carcinoma [4]. Furthermore, metastases also usually arise from the intraventricular or septal myocardium or involve the valvular apparatus. This case is unique in that the tumor was pedunculated and mobile in the RVOT. The “tethered ball” morphology resulted in symptomatic obliteration of the RVOT. RVOT pedunculated metastasis is extremely rare, but, as this case demonstrates can lead to dynamic obstruction. It should be considered in the differential diagnosis of dyspnea or chest discomfort in the patient with cancer, and echocardiography should be done with particular attention to the RVOT on parasternal long axis and subcostal short axis views as demonstrated.