Intrapericardial Paraganglioma Presenting as Chest Pain
A 50-year-old woman was admitted with angina. Her past medical history included poorly controlled hypertension and mild Parkinson’s disease. A systemic examination was unremarkable apart from a slight resting tremor. Serial ECGs and 12-hour postadmission troponin levels were normal. Echocardiography confirmed normal biventricular function and no left ventricular hypertrophy. A 12-lead exercise stress ECG was stopped at stage 2 of the Bruce protocol because of shortness of breath. The patient had achieved 82% of her target heart rate with no ischemic ECG changes.
Selective coronary angiography was performed and showed normal left anterior descending and circumflex arteries. However, the right ventricular branch of the right coronary artery appeared to supply a vascular mass (Figure 1 and Data Supplement Movie I). Subsequent computed tomography and magnetic resonance imaging demonstrated an intrapericardial mass with compression of the right pulmonary vein and the posterior wall of the superior vena cava (Figures 2 and 3⇓). There was no evidence of metastases. Her 24-hour urine norepinephrine level was elevated to 344.6 μg/d (normal, 10 to 150 μg/d), with normal epinephrine and dopamine levels measured at 6 μg/d and 201 μg/d (normal values <12 μg/d and 130 to 1200 μg/d), respectively. Surgical intervention was planned, and a multinodular encapsulated intrapericardial tumor with a gray-tan appearance measuring 2.5×3.0×4.0 cm was resected. There was no evidence of any intracardiac extension. Histological analysis of the tumor confirmed a compact nested appearance (the German expression is zellballen, meaning balls of cells), giving rise to a pseudoglandular pattern (Figure 4). The cells displayed a granular eosinophilic cytoplasm, central nuclei, and prominent nucleoli with no mitotic features. Immunohistochemistry was strongly positive for chromogranin A (Figure 5) and synaptophysin in the tumor cells. S-100 staining was highly positive in the surrounding sustentacular cells (Figure 6) and staining for cytokeratin was negative, thereby excluding a carcinoid tumor. The histological and clinical appearances were those of an intrapericardial paraganglioma.
The patient recovered uneventfully from surgery and maintains excellent blood pressure control with bendrofluazide. Subsequent 24-hour urine collection 22 months after surgery demonstrated normal norepinephrine, epinephrine, and dopamine excretion.
Catecholamine-secreting tumors arise from the neural-crest cells and have an annual incidence of 1 to 2 per 100 000. Eighty percent arise within the adrenal glands (pheochromocytomas), and the remaining 20% are extra-adrenal (paragangliomas).1 Two percent of paragangliomas are within the chest. These may originate within the mediastinum, lungs, heart, or esophagus. The majority of the mediastinal paragangliomas are found in the anterior or posterior aortopulmonary groove and are largely nonfunctioning.2 Functioning intrapericardial paragangliomas are exceedingly rare. More than 90% of paragangliomas are benign and compress adjacent structures as they enlarge, resulting in chest pain, dyspnea, cough, dysphagia, or hoarseness. However, a minority are locally invasive and exhibit distal metastases.3 Echocardiography, computed tomography, and magnetic resonance imaging help localize a paraganglioma. 131I-metaiodobenzylguanidine scintigraphy shows paragangliomas as areas of intense uptake. Plasma and urinary catecholamine levels may be raised if a tumor is functioning. Complete resection of the tumor is curative, although ligation of the feeding vessels leading to infarction in a surgically unresectable tumor has been described in the literature.4 Histological and immunochemical analyses are invaluable diagnostic adjuncts in establishing the diagnosis.
The online-only Data Supplement is available with this article at http://circ.ahajournals.org/cgi/content/full/119/12/e373/DC1.