Cardiac Metastasis of Malignant Melanoma

A 56-year-old male patient was diagnosed 6 years ago with left eye choroidal melanoma presented with progressive visual loss. Left eye enucleation was done. He is known for coronary artery disease and had pacemaker implantation for a complete heart block. The patient has pelvic and right orbital metastasis and is currently on dual immunotherapy. He was sent for echocardiography for routine follow-up.

Transthoracic echocardiography with intravenous contrast showed multiple homogenous myocardial masses on the interventricular septum, apex, and proximal interatrial septum. Left ventricular systolic function was mildly impaired. No valvular lesions were noted [Figure 1].

Figure 1.

Transthoracic echocardiography apical four-chamber view (a) and apical two-chamber views (b). Images (c) and (d) are the corresponding images with left ventricular contrast. The multiple well-circumscribed masses are marked by blue arrows

The patient was sent for cardiac magnetic resonance which also revealed well-defined iso-to-hypointense (melanin-containing) homogenous masses in the left, right ventricular myocardium, and interatrial septum. T1 postgadolinium showed intense enhancement of myocardial lesions [Figure 2].

Figure 2.

Cardiac magnetic resonance imaging long-axis four-chamber views: (a) Single cut from four-chamber CINE bright blood SSFP showing well-defined iso-to-hyperintense (melanin containing) homogenous masses (yellow arrows) in the LV and RV myocardium as well as the interatrial septum (yellow arrows). b) Four-chamber T1 postgadolinium administration showing intense enhancement of the myocardial lesions (yellow arrows). LV: Left ventricle, RV: Right ventricle, LA: Left atrium, SSFP: Steady-state free precession

Positron emission tomography (PET) and computed tomography showed an intense radiotracer uptake in the aforementioned myocardial masses [Figure 3].

Figure 3.

Positron emission tomography/computed tomography axial images: (a) Pre-FDG administration axial computed tomography chest level, showing ill-defined hyperdense lesions (yellow arrows) scattered in the myocardium. (b) Corresponding post-FDG axial image at the same level showing intense radiotracer uptake in the aforementioned myocardial masses (yellow arrows). LV: Left ventricle, RV: Right ventricle, FDG: Fluorodeoxyglucose

These findings are very suggestive of the hyperenhancing malignant melanoma metastasis with the rich capillary network.

Ocular melanoma is diagnosed in approximately 6 million people annually.[1] However, ocular melanoma metastasizes less frequently than cutaneous melanoma (75% vs. 96%, respectively). When it does metastasize, it is invariably fatal. Liver metastasis is the most frequent (90%). Later reports suggested that cardiac metastases are extremely uncommon and clinically underdiagnosed.[1]

Later autopsy reviews estimated that cardiac metastasis from ocular melanoma was found in approximately one-fifth of patients who die of this tumor. It mainly involves the myocardium (98%) and also the epicardium and the endocardium (78% and 73%, respectively).[2,3] PET is particularly helpful for staging of melanoma and assessing the response to treatment.

In the literature, cardiac metastasis leading to arrhythmia is very rare. Our case has had complete heart block and needed pacemaker insertion.[4]

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.