Intracavitary melanoma of the left atrium

Surgical management of the patient with metastatic melanoma to the heart

Melanoma has a high propensity for cardiac seeding, with heart involvement noted in a significant number of patients at autopsy. Therapeutic options are currently limited, and the prognosis of cardiac metastasis is poor. We report two cases of cardiac metastasis of melanoma and review the current literature. In addition, we propose an algorithm for dealing with this difficult problem.

Case report and literature review: surgical treatment of a right atrial metastatic melanoma from a previously resected "advanced" primary site with regional lymph nodes involvement

Although melanoma of the right atrium is a rare cardiac tumor, melanoma in general has a high propensity to involve the heart. Unfortunately, however, when the tumor is involving the heart, widespread metastasis ensues and hence surgery becomes a questionable option. We report a case of a young female who presented with an advanced skin primary melanoma and regional lymph node involvement and a metastasis into the right atrium. Postoperatively tumor dissemination was controlled with adjuvant chemotherapy. A vigorous attempt aiming at tumor clearance followed by adjuvant multimodality therapy along with a tumor surveillance program may improve survival even in advanced cases.

Metastatic malignant melanoma manifesting as an intracardiac mass

INTRODUCTION

Antemortem diagnoses of intracardiac metastases are uncommon. Metastatic melanoma shows a propensity for cardiac involvement, but cardiac involvement by melanoma is rarely identified clinically due to a paucity of cardiac symptoms.

METHODS

The surgical pathology files of Mayo Clinic were searched for cases of metastatic melanoma presenting or manifesting as an intracardiac mass. The lesions were evaluated pathologically for diagnoses. Clinical information was obtained by chart review.

RESULTS

Seven patients, four female and three male (age 31 to 79 years), were identified. No patient had a history of metastatic melanoma. All patients presented with dyspnea and symptoms of outflow obstruction. Echocardiography or CT revealed an intracardiac mass (four atrial, three ventricular). Six cases involved the right side of the heart and one involved the left ventricle. Five of the seven patients had a history of malignant melanoma, but none had a history of metastases when they presented with cardiac symptoms. In four cases, the history of primary melanoma was remote, occurring 7, 9, 13, and 28 years prior to the discovery of their cardiac mass. One patient had no history of melanoma, and no primary melanoma was ever identified. One patient had a history of a benign melanocytic lesion biopsied 2 years before, but retrospective review showed malignant melanoma.

CONCLUSIONS

Melanoma is known to have an unpredictable and prolonged course. Neoplastic involvement of the heart should be considered in patients with cardiac symptoms when a documented malignancy exists, no matter how remote.

Surgical treatment of malignant melanoma

The surgical management of melanoma has evolved over the last 100 years. when early concepts of lymphatic permeation of the tumors and metastases led surgeons to perform radical operative procedures. Wide excision of primary melanoma is now performed with 1- to 2-cm radial margins, significantly reducing the need for complex plastic closures, skin grafts. and hospital admissions. Although elective lymph node dissection remains controversial as a therapeutic procedure, the development of SL has improved the staging of the regional lymph nodes and diminished the morbidity of lymph node dissection. The role of SL for routine care of melanoma patients remains unknown. Metastasectomy, which is the surgical resection of distant metastases with tumor-free surgical margins, has not been popular for AJCC stage IV patients with multiple metastases, because surgery is considered a local therapy and therefore of little value for management of disseminated disease. Nevertheless, the many reports of long-term survival after resection of distant melanoma metastases to diverse soft tissue and organ sites clearly indicate that this form of cytoreductive surgery can be extremely successful in carefully selected patients. Unlike chemotherapy, complete surgical metastasectomy can rapidly render a patient disease-free with only a short period of postoperative morbidity. Most patients fully recover from the surgical procedure within 6 weeks, returning to most or all activities. The ability to select patients for surgery is based on the development of more sophisticated imaging techniques, which allow better preoperative differentiation of patients with single versus multiple metastases and improve the surgeon's ability to identify and resect multiple metastatic sites. The overall data suggest that patients whose metastases can be completely resected will experience improved overall survival and occasional long-term cure regardless of the metastatic organ site and number of metastases. We believe that increased understanding of the biology of the primary and metastases, dramatic improvement in the accuracy of staging metastatic disease, and better techniques of surgical resection provide the best chance for long-term palliation or cure of melanoma. Cytoreductive surgery should be considered a form of immunotherapy. The long-term clinical benefit of this therapy depends on the patient's immune response to, the surgical reduction in tumor burden: an immune response that controls subclinical micrometastases should optimize postoperative survival.

Isolated amelanotic malignant melanoma of the heart

We report a 58-year-old woman presenting with dyspnoea and recurrent pulmonary embolism. Echocardiography revealed pericardial effusion and a tumour located in the atrioventricular groove. Surgical exploration showed tumorous infiltration of the ventricle wall and of parts of the atrium. Curative excision was not possible and the operation was discontinued. Histology revealed an amelanotic malignant melanoma. No other tumour location was detected by scanning procedures. This case represents a very rare manifestation of melanoma exclusively located in the atrioventricular groove of the heart leading to recurrent pulmonary embolism. A review of the literature on cardiac involvement of melanoma is provided.

Metastatic ocular melanoma to the left ventricle inducing near-syncope attacks in an 84-year-old woman

Cardiac tumors may represent mechanical causes for syncope by limiting left ventricular filling and/or by obstructing the left ventricular outflow tract. Malignant melanoma is known to metastasize to the myocardium or pericardium, but there are only a very limited number of reports describing endocardial involvement by the tumor. We describe herein an 84-year-old woman who presented with daily near-syncope episodes, 9 years after treatment for a choroidal melanoma. The echocardiography and the pathologic examination revealed a metastatic melanoma. This is the first reported case of an ocular melanoma metastasizing to the heart and presenting as a left ventricular intracavitary pedunculated mass.

Resection of a right atrial metastatic melanoma with unknown origin of primary tumor

Cardiac involvement of malignant melanoma is generally part of a widespread tumor dissemination, which is mostly multifocal. Hence the disease is usually not amenable to surgical intervention. We report successful resection of a large intracavitary melanoma to the right atrium, the primary origin of which was unknown. The right atrium was reconstructed with an autologous pericardial patch. At 12-month follow-up the patient remains asymptomatic.

Complete resection of a right atrial intracavitary metastatic melanoma

We report a case of complete resection of a very large intracavitary metastatic melanoma of the right atrium. We describe a technique for resecting without damaging the atrium and for preventing the narrowing of the right atrium. In such cases, complete resection may be indicated despite widespread disease.