ORIGINAL ARTICLES  ADVANCES IN PET - PART II 

The Quarterly Journal of Nuclear Medicine and Molecular Imaging 2008 March;52(1):84-8

Copyright © 2008 EDIZIONI MINERVA MEDICA

language: English

Diagnostic value of serum chromogranin-A combined with MIBG scintigraphy in patients with adrenal incidentalomas

Giovanella L. ^{1, 2}, Ceriani L. ¹, Balerna M. ², Keller F. ², Taborelli M. ³, Marone C. ⁴, Ferone D. ⁵

¹ Department of Nuclear Medicine Oncology Institute of Southern Switzerland Bellinzona, Switzerland 2 Clinical Chemistry and Immunochemistry Central Laboratory EOLAB-Regional Hospital Bellinzona, Switzerland 3 Laboratory of Cytogenetics and Molecular Biology Oncology Institute of Southern Switzerland Bellinzona, Switzerland 4 Department of Internal Medicine and Nephrology Regional Hospital, Bellinzona, Switzerland 5 Institute of Endocrinological Sciences University of Genoa, Genoa, Italy

Aim. Adrenal incidentalomas (AI) are defined as asymptomatic adrenal masses occasionally discovered during high-resolution imaging procedures, as computed tomography or magnetic resonance. Pheochromo-cytoma, a chromaffin tumor, must be excluded before any invasive diagnostic or therapeutic procedure, in order to avoid dangerous acute catecholamines-release into bloodstream. Chromogranin-A (CgA) is a member of the granin family contained in secretory vesicles of chromaffin adrenal cells. Consequently, serum CgA increases in patients affected by pheochromocytoma and other diseases of the chromaffin system. This study investigated the performance of serum CgA in detecting or excluding pheochromocytoma among patients with AI.
Methods. We enrolled 348 patients affected by AI >20 mm without clinical or biochemical signs for corticosteroids overproduction. Serum CgA was assayed by a specific immunoradiometric method and a [123I]metaio-dobenzylguanidine (MIBG) scan was performed in the 39 CgA-positive patients.
Results. Eighteen out of these patients showed a positive scan and were submitted to laparoscopic adrenalectomy. Pheochromocytoma was histologically confirmed in all cases. The patients with positive serum CgA, but negative scan, as well as those with negative serum CgA, were reassessed 1 year later by clinical examination and serum CgA assay. None of patients developed clinical symptoms of chromaffin-tissue hyperactivity, nor showed a serum CgA increase. Serum levels of CgA were significantly higher in patients with pheochromocytoma than in patients without (P<0.0001).
Conclusion. We concluded that serum CgA assay is effective as a single marker to detect or exclude sporadic pheochromocytoma among patients with AI >20 mm. Particularly, a negative serum CgA assay may be used to rule out [123I]MIBG imaging and/or other diagnostic procedures.