Malignant Cardiac Pheochromocytoma With Bone Metastases
A 25-year-old man was referred to our hospital because of an abnormal shadow in the mediastinum, detected by gallium scintigraphy, and bone fractures. Three weeks before admission, he experienced severe neck pain while practicing golf at a driving range. The next morning, he was brought to a neurosurgeon by ambulance because the pain had become more severe and he was beginning to lose consciousness. A cervical radiograph showed a C4 compression fracture, and 99mTc bone scintigraphy depicted abnormal shadows in the left frontal bone, C2, C4, Th10, and right 8 rib. Gallium scintigraphy suggested a tumor in the mediastinum (Fig 1⇓).
Physical findings at admission, including blood pressure of 110/62 mm Hg, were within normal limits except for a pulse rate of 110 bpm. Echocardiography, MRI, and spiral CT showed a tumor located at the roof of the atria and penetrating into the right atrium and right ventricle (Fig 2⇓). The size of the tumor was estimated to be 8×6×8 cm. Plasma norepinephrine was 3010 pg/mL (normal, 40 to 350 pg/mL), plasma epinephrine was 25 pg/mL (normal, <120 pg/mL), and plasma dopamine was 9720 pg/mL (normal, <30 pg/mL). Urine norepinephrine was 965 μg/d (normal, 10 to 150 μg/d), urine epinephrine was 24 μg/d (normal, <12 μg/d), and urine dopamine was 11 490 μg/d (normal, 130 to 1200 μg/d). A [131I]MIBG scintiscan was negative except in the area in the mediastinum. A biopsy of the tumor at the left frontal bone revealed a nested “zellballen” pattern (Fig 3⇓). Tumor cells contained Grimelius-positive argyrophilic granules and were immunohistochemically positive with neuron-specific enolase and chromogranin A, which were quite compatible with paraganglioma. A biopsy of the cardiac tumor, guided by echocardiography, showed a tumor cytologically similar to the frontal bone with the same immunohistochemical reaction, although the tumor architecture was slightly obscured because of sampling crush (Fig 3⇓). Angiography showed that the cardiac tumor obtained its feeding vessels from the right coronary artery, the left circumflex branch of the coronary artery, and the left internal mammary artery. The tumor was hypervascular and showed tumor stain. Ambulatory blood pressure was within the normal range, although sinus tachycardia of ≈151 000 beats per day was detected. Radiation therapy was performed instead of surgical resection because of metastases.
Clinically, pheochromocytoma is defined as a functioning tumor that secretes catecholamines, whereas paraganglioma does not. However, histological differentiation of these two tumors is difficult. The term “functioning paraganglioma” is often used instead of pheochromocytoma.
We thank Dr Kazuo Nagashima for his advice.
The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD, Chief, Department of Pathology, St Luke’s Episcopal Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.
Circulation encourages readers to submit cardiovascular images to Dr Hugh A. McAllister, Jr, St Luke’s Episcopal Hospital and Texas Heart Institute, 6720 Bertner Ave, MC1–267, Houston, TX 77030.
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