Atypical Cardiac Location of Melanoma of Unknown Origin.

The subject was a 66-year-old woman, suffering from the chest pain evoked by physical activity. Transthoracic echocardiography (TTE) revealed an abnormal structure, 41 × 29 mm. In MSCT, a hypodensic mobile tissue lesion that was infiltrating the whole thickness of left ventricle was confirmed. PET excluded the existence of other remote lesions. After surgical tumor removal, histopathological differential diagnosis revealed melanoma, myoepithelial cancer, and MPNST "high-grade" sarcoma. A control TTE detected a tumor that was 14 × 10 mm. After immunohistochemical results, immunotherapy with pembrolizumab was used, which resulted in complete tumor resolution. Presently, surgical resection and neoadjuvant targeted immunochemotherapy remain the treatment of choice for clinical stage III/IV melanoma.