Limited role of meta-iodobenzylguanidine scintigraphy in imaging phaeochromocytoma in patients with multiple endocrine neoplasia type II

Objective: To compare diagnostic applicability of combined computed tomogra phy (CT) and magnetic resonance imaging (MRI), with that of meta-iodobenzyl guanidine (MIBG) scintigraphy in the preoperative localisation of MEN II re lated phaeochromocytoma. Design: Retrospective study Setting: University hospital, The Netherlands. Materials: 17 patients with MEN II patients (33 adrenal glands) who were op erated on for phaeochromocytoma. MIBG scintigraphy, CT and MRI were used to localize phaeochromocytoma. Histopathologically, an adrenomedullary lesion more than 1 cm in size was classified as a phaeochromocytoma. Main outcome measures: Sensitivity, specificity, and diagnostic accuracy of combined CT and MRI and MIBG scintigraphy, compared with histopathological findings. Results: Sensitivity of combined CT and MRI (27 adrenal glands) was 87%, wi th a specificity of 100% and a diagnostic accuracy of 89%. MIBG scintigraph y (31 adrenal glands) had a sensitivity of 92%, a specificity of only 17%, and a diagnostic accuracy of 77%. Conclusion: If unilateral adrenalectomy is done when only one adrenal gland contains a phaeochromocytoma, then MRI should be the method of choice for localising MEN type II related phaeochromocytoma. MIBG scintigraphy can be restricted to those patients in whom MRI does not show a tumour.