Cardiac metastasis from renal cell carcinoma without inferior vena involvement: a review of the literature based on a case report. Two different patterns of spread?

We report the case of a 59-year-old man with advanced renal cell carcinoma (RCC), without inferior vena cava (IVC) involvement, treated with radical nephrectomy, palliative radiotherapy for bone metastasis, and medical therapy for bone and lung metastases. The patient died of cardiac arrest after evidence of massive malignant pericardial effusion. At autopsy, massive myocardial and pericardial neoplastic invasion was found. Heart involvement via the IVC is a well-known phenomenon during RCC progression, while in the absence of IVC involvement, clinically evident cardiac involvement is exceptional, with few cases reported in the worldwide literature. Analysis of prior reports and of the present case provides evidence on how the cardiac metastasis may have two distinct origins and clinical features. The first is hematogenous, via the IVC, even in the absence of renal vein involvement; it is generally circumscribed and has a good prognosis after surgery. The second is through the intrathoracic lymphatic system, in the presence of disseminated disease, especially pulmonary metastasis, and this type has a very poor prognosis.