Endocrine Abstracts

Controlateral recurrence of pheochromocytoma is frequent in MEN2 patients. Cortical sparing adrenalectomy is currently recommended in this situation, but conveys a risk of adrenal insufficiency in up to 45 % of patients. The natural history of recurrent pheochromocytome is poorly known. Thus, appropriate timing of surgery and the possibility to postpone safely surgery remain debatable. We report our experience of long-term follow up of non-operated 16 pheochromocytomas in 13 MEN2 carriers. At diagnosis of MEN2 pheochromocytoma, 11/13 patients were normotensive and 2 were treated with calcic inhibitors. 7/13 had normal metanephrines values, contrasting with abnormal imaging studies. 6/13 had a median metanephrine level of 1.8 x ULN (range : 1.1 – 4.0 x ULN). Median tumor size at diagnosis was 12 mm (range : 8 – 24 mm). During follow-up (median duration of follow-up 5 years ; range : 2 – 26 years), median tumor growth was 0.5 mm/year (range : 0 – 2.1 mm/year). Among the 7 initially ‘non-secreting’ patients, metanephrine levels increased from 1.2 to 4.6 x ULN in 5 patients and remained normal in 2 patients. Among the initially ‘secreting’ patients, metanephrines increased from 1.8 to 4.6 x ULN. Tumor growth and metanephrine increments were correlated (r=0.8, P<0.01). No hypertension was reported in initially normotensive patients. No morbid cardiovascular event occurred in any patient. Surgery of 7/16 pheochromocytomas was performed after 2 to 26 years of follow-up. The reasons were : occurrence of mild symptoms (heart palpitations) in 4 patients, absence of previous contralateral surgery in 3 patients. Despite delaying surgery, parameters of per-operative hemodynamic instability were significantly milder than those of a control group of hypertensive sporadic pheochromocytomas (P<0.05).

Conclusion: tumoral and secretory progression is slow in MEN2 pheochromocytomas. In early-stage, asymptomatic recurrence, a careful follow-up allows to postpone safely complementary surgery and its attendant risk of adrenal insufficiency.