[Personal experience in diagnosis and localization of pheochromocytoma].

INTRODUCTION

Pheochromocytomas are most commonly tumours of adrenal medullary origin. Pheochromocytoma by definition produces and secretes catecholamines. Similar tumours that do not secrete active substances of any kind are called non functioning paragangliomas. The hallmark clinical manifestation of pheochromocytoma is hypertension accompanied with various signs and symptoms in excess of catecholamines or other bioactive substances. The early diagnosis of pheochromocytoma is important not only because it offers the possibility of curing hypertension but also because unrecognised pheochromocytoma is a potentially lethal condition. The aim of this article is to stress the specify of the clinical finding, diagnostical values of the laboratory tests and possibilities of morphological localizing techniques in a series of 98 patients with surgically proven pheochromocytoma.

RESULTS

Over the period from 1954 to 2002 pheochromocytoma was diagnosed and surgically treated in 98 patients. The diagnosis was confirmed at operation except in patients who refused operation or continued the examination in other Clinical wards. There were 59 females and 48 males (F:M = 1.23:1), the age ranged from 7 to 64 years with the pick incidence in the second and third decades of life in males and the third and fourth decades of life in females. The basic clinical characteristic was hypertension which was found in 94% of patients with an approximately equal frequency of fixed and paroxysmal hypertension cases. The most often accompanning manifestations were headache (62%), perspiration (61%) and palpitations (65%). A high level of vanyl mandelic acid (VMA) and free catecholamines in 24-hour urine collection confirmed the diagnosis in 94% of cases. In boderline cases we performed dynamic tests, the most relevant among them being the test with phentolamin. It was positive in 95% of patients. Retropneumothomography contributed to a successful localisation of tumour in 83% of cases. Computed tomography (CT) was performed in 69 patients and was positive in 97% of them. Magnetic resonance imaging (MRI) localized the tumour in all 16 patient in whom it was performed. The whole body MIBG-J-131 (metaiodobenzylguanidine) scanes were positive in 92% (45/49) and false negative in the remainder of 8% (4/49) of cases. Selective angiography was performed in 40 patients and in all it was positive.

DISCUSSION

Although pheochromocytomas were among the first recognized adrenal tumours, the prompt and safe diagnosis is mandatory up to date. The average annual incidence has been estimated by several epidemiologic studies to range from 0.8 to between 1.55 and 2.1 million persons per year. It is reported that it is curable cause of hypertension in 0.1% to 1% of cases. Pheochromocytoma has been classified as a "10% tumour" because various studies have shown that each of the characteristics mentioned bellow occurs with a frequency of approximately 10%: bilateral, extra-adrenal, multiple, malignant, familial and occurring in children. Our series of patients has a similar distribution: pheochromocytoma was in 9.2% of patients extra-adrenal, in 7.1% bilateral, in 9.2% multiple and in 4.08% malignant. Hypertension was the constant finding in 94% of our patients. Three clinical patterns of hypertenson have been observed. The first is paroxysmal hypertension, and the others are fixed or combinations of fixed and paroxysmal hypertension. According to our experience there were the equal incidence of all forms of hypertension. We noticed, like others, when the triad of headache, sweating and palpitations is accompanied by hypertension, the diagnosis of pheochromocytoma can be made with specify and sensitivity over 93%. In absence of this finding the diagnosis can be excluded with certainty of 99%. As a specify of the clinical finding, we mention two patients with manifestations of hypercorticism, two patients with pheochromocytoma of the urinary bladder, and four with MEN syndrome (one with MEN 2A and three with MEN 2B). For confirming the diagnosis the most relevant laboratory test was the higher level of VMA and free catecholamines in 24-hour urine collections. Once pheochromocytoma has been diagnosed by biochemical analyses, the anatomic location of the tumour or tumors must be determined. Currently, the best approach is to obtain MIBG-J-131 scan and then to perform MRI or CT of the abdomen and other areas identified on MIBG scan in order to provide more accurate spatial information. With this approach the great majority of pheochromocytomas can be localized.

CONCLUSION

There is no classic picture, no stereotype for pheochromocytoma, although the history and physical finding are helpful. Patients come to the clinician in a variety of ways and settings. They may have classic attacks of hypertension accompanied with headache, perspiration and paplpitations or they may have identical symptoms and physical findings as the patients with primary hypertension. On the other hand, they may have signs and symptoms of diabetes mellitus, hyperthyroidism, hypercalcaemia, congestive heart failure, myocardial infarction, malignant hypertension or a variety of other conditions. Rarely, they have no complaints at all. Once the diagnosis was made, spatial localizing of the tumour or tumours, and surgical treatment are necessary. Unrecognized disease may be fatal.