Clinical and Endocrinologic Differences between Prolactinoma and Pseudoprolactinoma Proven by Immunohistochemical Study / 대한내분비학회지

Hyperprolactinemia is the most common hypothalamo-pituitary disorder encountered in clinical endocrinology. Excluding the drug-induced hyperprolactinemia, the most common cause of this disorder is a pituitary tumor. Prolactinoma is mainly made up of prolactin-secreting cells but pseudoprolactinoma is tumor that does not secrete prolactin itself. The pseudoprolactinoma interrupts the flow of prolactin inhibiting factor, dopamine, from the hypothalamus through the pituitary stalk to the normal pituitary. The differentiation prolactinoma from pseudoprolactinoma is vitally important since true prolactinomas are most commonly responded well in terms of tumor shrinkage to medical treatment using dopamine agonist therapy, whereas pseudoprolactinomas do not. Thus surgical treatment is clearly indicated as first-line treatment if we know that a lesion is a pseudoprolactinoma. We compared prolactinoma with pseudoprolactinoma in clinical and endocrinologic characteristics of 48 cases after immunohistochemical diagnosis. We could not find any differential point of both tumors in clinical and radiological characteristics although some differences were exist. But we had found the relationship between the mean level of pretreatment serum prolactin and the presence of positive immunohistochemical stain for prolactin. The pretreatment serum prolactin level was significantly higher in patients with tumors showing many prolactin immunohistochemical staining cells than in those with none(p<0.05). When the pretreatment serum prolactin exceeded 100ng/ml, the tumors contain 94% of prolactin positive cells in stain. So, if the pretreatment serum prolactin exceeds 100ng/ml, we primarily suspect prolactinoma and medical treatment should be considered. If the pretreatment level below 100ng/ml, we suspect pseudoprolactinoma and surgical treatment should be considered.

Immunohistochemical Study of c / 대한내분비학회지

A large number of studies for genes involved in oncogenesis have been done during last decade. Over 20 oncogenes have been isolated characterized, and the oncogene expressions in human tumors have been examined. The proto-oncogenes of c-Myc, c-Fos and c-Jun, which modulate the transcription factors, have overexpressed in a variety of human cancers. Immunohistochemical method was used in this study to examine c-Myc, c-Fos and c-Jun oncoprotein expression in 31 patients with human pheochromocytoma 28(90.0%) were benign and 3(10.0%) malignant. C-Myc oncoprotein immunoreactivity was found in 24 cases(77.4%), c-Fos in 29(93.5%), and c-Jun in 25(80.6%). Twenty-one(67.7%) showed positive immunoreactivity for all these oncoproteins, six(19.4%) for 2 oncoproteins, 3 for one oncoprotein. Only 1 case showed negative immunoreactivity for all 3 oncoproteins. The oncoprotein immunoreactivity did not correlate with the amount of 24 hour urinary catecholamine excretion. Although the number of malignant pheochromocytomsa was not so many, most of them showed that the immunoreactivity for oncoprotein was more than 30 percent of tumor cells.The expression of c-Myc, c-Fos and c-Jun oncoprotein were frequently found in human pheochromocytoma. These results suggest that the oncoprotein expression may play an important role in tumorogenesis and proliferation of human pheochromocytoma.

Endocrinological and Morphological Characteristics of Clinically Nonfunctioning Pituitary Adenoma / 대한내분비학회지

Forth-nine patients with clinically nonfunctioning pituitary adenomas were evaluated clinically, endocrinologically and morphologically in this study.The results obtained were as follows.1) The mean age was 47.1 years(range 23 to 76 years), and 22 were male(44.9%) and 27(55.1%) female.2) The major clinical manifestations of male patients were visual disturbance(72.7%), headache(54.5%), loss of libido(45.5%), but those of female visual disturbance(59.6%), headache(48.1%), amenorrhea(48.1%), loss of body hair(25.9%), and galactorrhea(22.2%).3) All were macroadenomas evaluated by CT scan, and in the male patients 16(72.7%) were grade III and 6(27.3%) grade IV by Hardy classification, and in the female patients 6(22.2%) were grade II, 12(44.4%) grade III, and 9(33.3%) grade IV.4) The elevation of serum prolactin were observed 7(31.8%) out of male, and 24(88.9%) of female.5) Combined stimulation test revealed that GH insufficiency was 89.6%, ACTH 58.9%, LH 58.7%, FSH 51.1 %, and TSH 50.0% and hormone insufficiency more than 4 pituitary hormone was 54.2%.6) Prolactin response to TRH decreased in 12(70.6%) of 17 patients with normal basal prolactin, and 19(76.0%) of 25 with elevated prolactin.7) Immunohistochemistry revealed that null cell adenoma was 57.1%, gonadotrope adenoma 26.5%, plurihormonal adenoma 8.0%, silent corticotrope adenoma 4.0%, thyrotrope adenoma(2.0%), and lactotrope adenoma(2.0%).8) The ultrastructural characteristics examined by electron-microscopy were similar despite of immunohistochemical differences.In summary, the prevalance of clinically nonfunctioning pituitary adenoma was middle aged men and women, and their main symptoms were visual disturbance and headache. Hyperprolactinemia and pituitary hormone insufficiency more than 4 hormone were observed commonly. Most of them were null cell adenoma and gonadotrope adenoma examined by immunohistochemistry. Further study using modern techniques: cell culture, subunit-immunostaining. And Northern blot analysis of mRNA for pituitary hormone or subunit, will be needed to clarify null cell adenomas.

In Situ Hybridization Analysis of Human Growth Hormone and Prolactin Secreting Pitultary Adenomas / 대한내분비학회지

A non-isotopic in situ hybridization method with biotin-labelled oligonucleotide probes was used to examine growth hormone(GH) and prolactin(PRL) gene expression in 32 patients with pituitary adenomas; 13 were prolactinomas, 8 GH secreting adenomas, and 11 mixed GH and PRL secreting adenomas.Positive immunostaining for GH was found in all patients with GH secreting adenomas, and mixed GH and PRL secreting adenomas. Positive immunostaining for PRL was found in all patients with prolactinomas and 9(81.8%) of 11 mixed GH and PRL secreting adenomas, 5(62.5%) of 8 GH secreting adenomas. Immunohistochemistry revealed that 13 were lactotrope adenomas, 5 somatotrope adenomas, and 14 GH and PRL cell adenomas.In situ hybridization revealed that GH mRNA expression was found in all the patients with somatotrope adenomas and GH and PRL cell adenomas, and 6(46.1%) of 13 lactotrope adenomas. PRL mRNA expression was 100% in lactotrope and GH and PRL cell adenomas, and 4(80.0%) of 5 somatotrope adenomas.The patients with a clinical diagnosis of acromegaly had detectable PRL mRNA in their neoplasm and it is suggested that the PRL cells in the adenomas did not result from dedifferentiation, but from the neoplastic stimulus for some mixed tumors probably occurred in cells previously committed to produce PRL and GH. In lactotrope adenomas, the PRL cells of the patients without expression of GH mRNA may be arised from cells programmed to secrete PRL or precussor PRL cells rather than from mixed GH-PRL cells. The finding that some patients produced mRNA detectable by in situ hybridization, but no hormone detectable by immunohistochemistry within tumor was suggested of a silent adenoma.These observations indicated that in situ hybridization studies may improve the classification of pituitary adenomas and may provide a precise knowledge of the biology of these neoplasms.