Endocrine Abstracts

Background: Chromaffin cell tumours are rare but potentially curable endocrine tumours. These tumours may be sporadic or familial in nature. Biochemical tests are normally performed initially, followed by radiological investigation.

Aim: To assess the correlation of biochemical and radiological investigations with histologically proven chromaffin-cell tumours in patients with sporadic and familial disease.

Methods: We retrospectively reviewed data for 28 patients who underwent adrenalectomy for presumed chromaffin cell tumours between October 2005 and October 2010.

Results: 18 of 28 patients underwent laparascopic adrenalectomy. 5 patients had MEN2A, 2 had NF1, 1 had VHL and 2 were SHDB+ve. Histology confirmed phaeochromocytoma in 19, 1 of which was malignant and 5 paragangliomas, 1 of which was malignant. Biochemical data were available for 21 patients. Pre-operative 24-hour urine catecholamines showed mean urine adrenaline 1.51±1.38 μmol (NR 0.00–0.10), mean noradrenaline 3.05±1.44 μmol (NR 0.00–0.50), and mean dopamine 2.10±0.41 μmol (NR 0.00–2.70). All patients with MEN2A, NF1 and VHL had negative urine catecholamines. Both patients with SHDB mutations had positive urine catecholamines. Two of the patients with MEN2A had urine metanephrines performed, one of which was positive despite negative urine catecholamines. Similarly, one of the NF1 patients had positive urine metanephrines with negative urine catecholamines. MIBG scan was positive in 18 of 20 patients; of the two patients with negative MIBG, one was also negative on Gallium-68 DOTATATE scan. One of the patients with MEN2A had a negative MIBG scan.

Conclusion: Our results show that urine catecholamines are poor markers in the detection of phaeochromocytoma in patients with familial syndromes. We have shown that the sensitivity of urine metanephrines is superior to that of urine catecholamines in patients with MEN2A and NF1. In addition, there are limitations to MIBG scanning; care needs to be taken in interpreting these scans in patients with a genetic predisposition to phaeochromocytoma.