Distinctive clinic features of pheochromocytoma in the setting of multipleendocrine neoplasia 2A

BACKGROUND: TO study distinctive clinical features of pheochromocytoma in t he setting of multiple endocrine neoplasia type 2A (MEN 2A) in comparison w ith sporadic pheochromocytoma. PATIENTS AND METHOD: All patients diagnosed of sporadic pheochromocytoma (n = 29) and in the setting of MEN 2A (n = 16) between 1976 and 1998 in a ter tiary hospital were included in the study. The following variables were com pared: age at diagnosis, symptoms, presence and characteristics of hyperten sion, size of the tumor, localization and malignancy. The accuracy of diagn ostic tests was also evaluated. RESULTS: The pheochromocytoma associated to MEN 2A had a higher prevalence in our study (35.5%) and the diagnosis was performed earlier than for spora dic pheochromocytoma (29.1 [7.8] vs. 47,5 [10.9] years; p < 0.001), Other d istinctive features in comparison with sporadic pheochromocytoma were: bila terality (81.25 vs. 3.44%; p < 0.001), absence of symptoms (44 vs 11%; p < 0.05) and paroxysmal hypertension. Concerning the diagnostic tests, it must be noted the low sensitivity (60%) of vanillylmandelic acid in MEN 2A. CONCLUSIONS: The pheochromocytoma in the setting of MEN 2A is diagnosed at younger age and frequently asymptomatic and bilateral. In view of the high prevalence of MEN 2A in our country, a genetic analysis should be performed in all patients with pheochromocytoma, especially when it is bilateral.