Abstract 17445: Near Occlusion of the Tricuspid Valve By Metastatic Melanoma

Abstract

Introduction: Metastatic tumors to the heart can have varied clinical presentations depending on location. We present a case of right atrial (RA) metastatic melanoma with near obstruction of the tricuspid valve resulting in significant hypoxia. Case Presentation: A 34-year-old man with a history of retinoblastoma and astrocytoma presented to the emergency department with 2 weeks of progressively worsening shortness of breath. On examination he was hypoxic and in respiratory distress. Computed tomography of the chest with contrast showed a large hypoattenuating homogeneous mass in the RA that protruded into the right ventricle and extended to the superior and inferior vena cavae. Transthoracic echocardiography (TTE) showed a large (9.1 x 4.6 cm) echodensity filling the RA and almost completely obstructing the tricuspid valve. Due to worsening hypoxia, the patient underwent palliative surgical resection of the mass. Intraoperatively, the mass was densely adherent to all walls of the RA. Surgical pathology identified the mass as metastatic malignant melanoma. The patient was started on pembrolizumab and discharged home in stable condition. At his 1-month follow-up, his symptoms had improved and he had returned to work. Discussion: Metastases to the heart are more common than primary cardiac tumors. Left-sided cardiac masses are commonly benign, whereas right-sided masses raise suspicion for metastatic disease. Melanoma, lymphoma, leukemia, and breast and lung cancers commonly metastasize to the heart. The size of the RA mass in this patient was significant enough to cause hypoxia and near occlusion of the tricuspid valve. Successful palliative resection of the mass resulted in a large improvement in symptoms. Conclusion: As the incidence of malignant melanoma increases, clinicians need to have a high index of suspicion for cardiac metastasis. Early identification of cardiac metastasis is critical as these cases can often be associated with poor prognosis.