Malignant melanoma with cardiac involvement: a case report and literature review

Introduction. Malignant melanoma is the tumor most frequently associated with cardiac metastases. Melanocytes originate from the neural crest, which may underlie the tumor’s propensity for widespread hematogenous dissemi-nation, including to the heart. Cardiac involvement is found in up to 64% of patients with melanoma at autopsy; however, antemortem diagnosis remains rare because patients are frequently asymptomatic. Case presentation. We report the case of a 42-year-old woman with malignant melanoma of the lumbar region and right atrial metastasis. Initial BRAF mutation testing of archival primary tumor tissue was nondiagnostic because of DNA degradation. Subsequent pyrosequencing of a subcutaneous metastasis detected the BRAF V600E mutation, which enabled targeted therapy. The patient received multiple lines of systemic therapy, includ-ing pembrolizumab, ipilimumab, and BRAF/MEK inhibitors (dabrafenib and trametinib). Serial echocardiographic monitoring demonstrated complete regression of the right atrial metastasis during BRAF/MEK inhibitor therapy, followed by recurrence upon disease progression. Electrocardiographic abnormalities, including sinus tachy-cardia, low QRS voltage, and nonspecific ST-T wave changes, were observed despite the absence of cardiac symptoms. The patient survived for approximately 3.5 years after the diagnosis of cardiac metastasis. Conclusions. This case demonstrates that BRAF/MEK inhibitor therapy can achieve complete resolution of cardiac metastases on transthoracic echocardiography. When initial BRAF testing is nondiagnostic, retesting of metastatic tissue using sensitive molecular methods may identify actionable mutations. An integrated mul-timodal imaging approach and routine electrocardiographic surveillance are recommended for patients with metastatic melanoma.