Metastatic squamous cell carcinoma of an unknown primary site with cardiac involvement: case report.

Head and neck squamous cell carcinomas frequently metastasize to cervical lymph nodes. Distant metastasis by hematogenous dissemination pathways is less common. Cardiac involvement is a particularly rare occurrence. The first case of cardiac metastasis was reported in the early 18th century as a postmortem discovery. Since then, there have been sporadic reports of oropharyngeal cancer with cardiac metastasis. This report describes a case of metastatic squamous cell carcinoma of an unknown primary site involving the lungs, heart, and soft tissue of the bilateral paraspinal regions and lower extremity.