Abstract 12450: Unusual Treatment of an Unusual Tumor
A 62-year-old male presented with exertional dyspnea and atypical chest discomfort for the last year. His medical history was significant for prostate cancer, treated with prostatectomy four years ago. Two years prior, he had developed pericarditis, which was treated with NSAIDs and colchicine. Physical examination revealed a soft systolic murmur at the left upper sternal border that increased with inspiration. High-resolution computed tomography demonstrated a 7 × 4 cm intrapericardial mass infiltrating into the right ventricle (RV). There was an adjacent prominent lymph node in the anterior mediastinum. Due to suspicion of a metastatic malignancy, a positron emission tomographic scan with 18-FDG was performed, which confirmed hypermetabolic focus in the RV along with mediastinal lymph nodes, thoracic vertebra 8 and sigmoid colon. Over the next 2 weeks, there was a marked progression in symptoms. A right heart catheterization demonstrated a significant RVOT gradient of 16 mm Hg at rest. Coronary angiography demonstrated that vascular supply to the cardiac mass arose predominantly from an atrial branch, the conus branch and the SA nodal branch of a non-dominant right coronary artery. In order to obtain tissue diagnosis, thoracoscopic biopsy of the anterior mediastinal lymph node was planned. Histopathological and immunochemical examination demonstrated presence of metastatic paraganglioma. Further laboratory testing confirmed elevated serum levels on dopamine in the patient. As complete surgical excision was deemed unrealistic, novel treatment with percutaneous alcohol ablation supplemented by implantation of Microvention coils in the tumor vasculature was pursued. Over the next few months, he had a marked improvement in his symptoms and functional capacity. Follow up imaging demonstrated a marked attenuation in the size of the cardiac tumor. Genetic work up revealed a deleterious mutation R230H in the succinate dehydrogenase B subunit enzyme, consistent with hereditary paraganglioma pheochromocytoma syndrome. His initial cyclophosphamide based chemotherapy regimen was changed to Temozolamide at that point. Two and a half years after the intervention, the patient continues to be asymptomatic with a significantly reduced tumor burden.
- © 2012 by American Heart Association, Inc.