Pheochromocytoma in Italy: a multicentric retrospective study

Objective: To conduct an epidemiological study on pheochromocytoma in Italy . Methods: Data on 284 patients with pheochromocytoma observed between 1978 a nd 1997 were collected from 18 Italian centers through a questionnaire repo rting epidemiological, clinical, laboratory, radiological and surgical data . Results: 53.6% of the patients were females and 46.4% were males. Thirty-tw o tumors were discovered as incidental adrenal masses. The most frequent re ferred symptoms were palpitations (58.1%), headache (51.9%), sweating (48.8 %) and anxiety (35.3%). Their association was present only in 15.5% of pati ents. Paroxysmal symptoms were reported in 67.1% and hypertensive crises in 59.7% of patients. Normal blood pressure (systolic and diastolic) was pres ent both in the supine and upright positions in 21.1% of patients. Among la boratory assays, urinary vanylmandelic acid (VMA) was the most widely used (58.1%) and was the least sensitive (25% of false negative results). Basal plasma catecholamines were found to be normal in 11.3% of patients but were always elevated when sampled during a hypertensive paroxysm. A clonidine s uppression test was performed in 38 patients with no adverse side effects, It gave a false negative response in 2 patients. A glucagon test was perfor med in 21 patients. It was interrupted for acute hypertension in 52.4% of p atients. Only 5/21 patients were normotensive and had normal basal plasma c atecholamines, In these patients the test gave a positive response in four (80%). CT (79.6%) and I-MIBG scintigraphy (68.5%) were the most widely used methods for tumor localization, CT sensitivity was 98.9% for intra-adrenal and 90.9% for extra adrenal tumors. MIBG sensitivity was 88.5%. In the 263 patients who underwent surgery, the tamer was intra-adrenal in 89.4%, extr a-adrenal in 8.5%, intra- and extra-adrenal in 2.1%, and bilateral in 11.0% of patients, Malignancy was reported in 9.9% of cases. Surgery caused remi ssion of hypertension in 59.3%, improvement in 26.8%, and no changes in 13. 9% of patients. In the last group the interval between initial symptoms and diagnosis was significantly longer, Conclusions: The present study confirms that the clinical presentation of p heochromocytoma is variable and aspecific, Normotension is often present an d often the tumor is discovered incidentally. An indication for the routine use of screening methods more sensitive than urinary VMA is strongly sugge sted. The clonidine test was found to be safe and should be preferred to th e glucagon test which has to be restricted to very selected patients. CT an d MIBG scintigraphy are almost always successful in localizing the tumor. R eversal of hypertension by surgery seems to depend on an early diagnosis.