Functioning Intrapericardial Paraganglioma
Multimodality Imaging Findings and Pathological Correlation
A 38-year-old man presented with a 3-month history of night sweats, nonproductive cough, and weight loss. He denied chest pain or shortness of breath. A transesophageal echocardiogram showed a large mass adjacent to the aortic root likely arising from the pericardium or the left ventricle (Figure 1 and Movie I in the online-only Data Supplement). Invasive coronary angiography revealed a highly vascular mass perfused by the left main artery causing deformity of the aortic root (Figure 2 and Movie II in the online-only Data Supplement).
Various imaging modalities were then performed to further characterize the lesion. Cardiac computed tomography angiography revealed a large heterogeneous, intensely enhancing mass within the pericardial sac, just above the anterior wall of the left ventricle, anterior to the left atrium and to the left of the ascending aorta. The mass was encasing the left main artery and the proximal left anterior descending artery (Figure 3).
Cardiac MRI revealed a large, well-circumscribed mass arising from the pericardium in the left paraaortic region. The mass was isointense to myocardium on T1-weighted images (Figure 4A) and highly hyperintense on T2-weighted images (Figure 4B). It did not demonstrate features to suggest invasion of the adjacent myocardium or vascular structures. Rather, it appeared to be displacing structures favoring a benign entity (Movie III in the online-only Data Supplement).
Computed tomography scans of the abdomen, pelvis, and head confirmed the absence of distant metastases.
Because the patient was hypertensive, a 24-hour urinary collection was performed, which demonstrated high levels of normetanephrine and metanephrine that are suggestive of a paraganglioma.
The patient underwent surgical resection of the mass, with 2 vessel coronary artery bypass grafts to the left anterior descending artery and circumflex arteries, because the left main artery was compromised by the tumor. At the time of surgery, a solid, well-encapsulated intrapericardial mass attached to the base of the aorta and pulmonary arterial root (Figure 5D) was found, and pathological examination of the specimen confirmed a paraganglioma (Figure 5A through 5C and 5E).
Paragangliomas are rare tumors of chromaffin cells arising from an extra-adrenal location. The majority of these tumors originate from the adrenal medulla and are known as pheochromocytoma. Intrapericardial paragangliomas are extremely rare1 and have been reported adjacent to the bifurcation of great vessels. They tend to be located in the aortopulmonary groove, close to the left atrium, at the level of the para-aortic sympathetic ganglia.1–3 The presenting symptoms are variable and may be related to catecholamine hypersecretion with hypertension, palpitations, headache, and sweating or may be attributable to the mass effect on adjacent structures. In some cases, when the tumor is nonfunctioning, they may present as an incidental finding.
Intrapericardial paraganglioma should be considered in the differential diagnosis of a well-circumscribed, highly vascular tumor, arising from the aortopulmonary groove demonstrating high signal intensity on T2-weighted sequences on MRI and intense contrast enhancement on computed tomography. The differential diagnosis should include other pericardial tumors, namely pericardial hemangioma, sarcoma, and metastases. Although imaging findings together with the presence of hypertension in a patient with catecholamine excess strongly suggest the diagnosis, tissue diagnosis is ultimately needed. Multimodality imaging plays an important role in planning a complete surgical resection, which is the curative treatment.
The online-only Data Supplement is available with this article at http://circ.ahajournals.org/lookup/suppl/doi:10.1161/CIRCULATIONAHA.114.012458/-/DC1.
- © 2014 American Heart Association, Inc.
- Rotolo N,
- Imperatori A,
- Bacuzzi A,
- Conti V,
- Castiglioni M,
- Dominioni L