Comparison of Immunohistochemical and Clinical Characteristics in Pituitary Adenoma with Acromegaly / 대한내분비학회지

ABSTRACT

BACKGROUND: It assumed that plurihormonal pituitary adenomas in acromegaly, which were immunohistochemically stained with other pituitary hormones in addition to GH and prolactin, would be originated from poorly differentiated cells. Therefore, we speculated that they might have higher growth rates and worse prognosis than monohormonal adenomas. To verify this speculation, we analyzed the frequency of plurihormonal adenomas and compared the clinical parameters and radiological invasiveness between plurihormonal adenoma and GH-prolactin adenoma in acromegaly. METHODS: We studied 38 patients with acromegaly (22 males and 16 females, mean age 40.7 years) who were underwent surgical removal of pituitary adenomas by TSA from January 1995 to February 1998. We performed immunohistochemical staining in these tumors using avidinbiotin peroxidase complex method. An adenoma was considered as immunoreactive when above 50 percents of tumor cells were stained with anti-hormonal antibodies. Invasiveness of tumors were evaluated by preoperative MRI findings on the basis of Hardys classification. RESULTS: The frequencies of plurihormonal and GH-prolactin adenomas were 42% and 58%, respectively. Plurihormonal adenoma included an adenoma which was not stained with prolactin, but with GH and other hormones. Prolactin immunoreactivity was found in 97%(37/38) of the tumors. Immunoreactivities to FSH, ACTH, LH, and TSH were found in 37.8%, 13.1%, 2.6% and 2.7%, respectively. There were no significant differences in age, basal serum GH and IGF-1 concentrations between plurihormonal and GH-prolactin adenomas. There were also no significant differences in response to TRH & LH stimulation tests and somatostatin & bromocriptine suppression tests between two groups. There were no differences in radiological invasiveness between two groups (plurihormonal adenoma, grade I 2, grade II 3, grade III 7, grade IV 4; GH-prolactin adenoma, grade I 3, grade II 6, grade III 9, grade IV 4). CONCLUSION: Plurihormonal adenomas were 44% and immunoreactivity to prolactin was 97% in pituitary adenomas in acromegaly. There were no significant differences in clinical parameters and radiological invasiveness between plurihormonal and GH-prolactin adenomas in acromegaly.