Pheochromocytoma

Abstract

Pheochromocytomas are catecholamine secreting tumors arising from the chromaffin cells of neural crest origin with prevalence of 0.1% to 0.6% in the hypertensive population. We describe our experience with 95 patients with pheochromocytoma from a tertiary care center in north India. Patients diagnosed with pheochromocytoma from 1996 to 2006 were studied. Details of the clinical manifestations, diagnostic workup including 24-hour urinary vanilyl mandelic acid (VMA) and/or urinary epinephrine (E) and norepinephrine (NE) along with localization modalities including ultrasonography (USG), CT scan of the abdomen, and meta-iodo benzyl guanidine scan were analyzed. Intraoperative details including fluctuation in blood pressure during surgery, size of the tumor, postoperative events, and follow-up records for the presence /resolution of hypertension, and recurrence of disease were also evaluated. A total of 95 patients (46 men), were diagnosed with pheochromocytoma during the study period. The mean age of these patients was 34 ± 15 years, and the lag time between the onset of symptoms and diagnosis was 2.5 ± 3.8 years. Eighty percent of the patients had an adrenal pheochromocytoma, whereas 19 (20%) were detected to have paraganglionomas. Two thirds of the patients were suspected to have pheochromocytoma because of hypertension and one of the components of paroxysmal triad. The rest were detected incidentally. Eighty-five patients (89%) were found to be hypertensive with 61 (72%) having sustained and 24 (28%) having labile hypertension. Elevated 24-hour urinary VMA and catecholamines (E/NE) were found in 41 (46%) and 37 (40%) patients. USG localized tumor in 88% and CT scan (adrenal or extra-adrenal) in 99% patients. Eighty-seven patients underwent surgical excision of the tumor. The mean tumor weight was 109 ± 193 g. Nine patients had malignancy as evidenced by distant metastases. At follow-up, 71% were normotensive with recurrence of disease in 11 patients including 9 with metastatic disease. The majority of patients with adrenal pheochromocytoma were young and one-third of them were detected incidentally. The paroxysmal triad was observed in two-thirds of the patients and majority of them had large tumors, which could even be localized by USG. Urinary VMA and catecholamines seems to be a poor tool for screening. Surgery was rewarding in that two thirds of the patients experienced resolution of hypertension.