[Cardiac pheochromocytoma. Failure of classic non-invasive diagnostic methods]

We report an exceptional case of cardiac pheochromocytoma which raised problems of localization. A 30-year old man who for several years had been hypertensive was admitted for attacks of paroxysmal hypertension. Very high levels of urinary catecholamines suggested a diagnosis of pheochromocytoma, but no tumour was found at computerized tomography (CT) and metaiodobenzylguanidine (MIBG) scintigraphy. However, regional venous samplings detected two para-carotid phaeochromocytomas which were surgically removed. Thereafter, the symptoms persisted and investigations were resumed. As new regional venous samplings persisted and investigations were resumed. As new regional venous samplings showed high levels of catecholamines in the right atrium, a mediastinal and, chiefly, cardiac phaeochromocytomas was suspected. No tumour was visible at CT or ultrasonography and another MIBG scintigraphy proved negative. Coronary angiography showed a very large tumour behind the left atrium, well supplied by the circumflex artery and by a branch of the right coronary artery. The patient was operated upon and is now totally asymptomatic after a 9-month follow-up. This case emphasizes the value of invasive methods (i.e. regional venous sampling and coronary angiography) in the localization of this ectopic tumour. In most cases, however, phaeochromocytomas can be localized by MIBG scintigraphy.