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.