In the present paper we evaluated the ability of pretargeted immunoscintigraphy (ISG) with antichromogranin A (CgA) monoclonal antibody (Mc-ab A11) in visualizing pituitary masses. The results obtained in 23 patients are described along with those of [111In]pentetreotide scintigraphy (Octreoscan®) in 18 cases. Positive ISG was obtained in 9/11 (82%) non-functioning, 1/4 growth hormone-, 1/2 prolactin-, 1/2 thyrotropin-, 1/1 follicle-stimulating hormone-, 0/1 adrenocorticotrophin-secreting pituitary adenomas. In one patient with a positive ISG scan of a non-functioning pituitary adenoma, an associated neurinoma of the acoustic nerve was not imaged. The same occurred in one patient with a pituitary deposit from a mammary carcinoma and in another one with a cyst of the Rathke's pouch. Chromogranin A immunohistochemistry, carried out in 10 tumours, was positive in eight pituitary adenomas and negative in two non-adenomatous lesions. A concordant ISG occurred in all cases except for two pituitary adenomas: one cystic and necrotized and one postoperative remnant very small in size, In 18 patients with pituitary adenoma both ISG and Octreoscan® were positive in 61% of cases but with a different distribution among tumours. At Variance with ISG, Octreoscan® visualized only 5/10 (50%) non-functioning pituitary adenomas and all (4/4) somatotropinomas. In conclusion, ISG is able to image pituitary tumours and particularly non-functioning pituitary adenomas. In this respect, it may be helpful in discriminating non-neuroendocrine masses of the pituitary region from non-functioning pituitary adenomas.
|Number of pages||6|
|Journal||European Journal of Endocrinology|
|Publication status||Published - Aug 1996|
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