Immunoreactive luteinizing hormone, follicle stimulating hormone and their subunits in tissue culture media from normal and adenomatous, human pituitary fragments.

Fragments from 4 human pituitaries removed at surgery from one gonadectomized man and three women (one with Nelson's syndrome, one with Forbes Albright syndrome and one with chromophobe adenoma) were grown in tissue culture. The tissue culture medium was changed at weekly intervals, pooled and applied to a Sephadex G-100 column for gel filtration. In each eluate luteinizing hormone (LH), follicle stimulating hormone (FSH), alpha subunit and the beta subunits of LH and FSH were measured by specific radioimmunoassays. For comparison the pituitary standard LER 907 was similarly studied. LH and FSH were measurable in all studies. LH eluted over a broad area whereas FSH eluted as a much sharper peak. In all culture media and in LER 907 large quantities of alpha subunit were detected. The beta subunits of LH and FSH were not present in the LER 907 standard. LHbeta subunit was present in the culture medium of the pituitary fragments from the castrated man and from the women with Nelson's syndrome and Forbes Albright syndrome but not in that of the woman with chromophobe adenoma. FSHbeta subunit was detectable only in the latter case.

Localization of prolactin in chromophobe pituitary adenomas: study of human necropsy material by immunoperoxidase technique.

In order to identify prolactin-producing tumours in human pituitary glands, 45 chromophobe adenomas, obtained from unselected necropsies, have been studied by various staining procedures including the immunoperoxidase technique for the demonstration of prolactin. The presence of immunoreactive prolactin was revealed in the cytoplasm of the tumour cells in six cases (13%), indicating that the occurrence of prolactin-producing adenomas is not rare. No correlations were established between tumours and clinical history. Two adenomas were detected in female and four in male patients. The age of the patients at necropsy ranged from 28 to 75 years. Three adenomas were associated with disseminated carcinoma, two with fatal liver disease, and one with diabetes mellitus, atherosclerosis, and pyelonephritis. Manifest endocrine symptoms were not disclosed, and endocrine investigations, including measurements of blood prolactin levels, were not undertaken. Thus, direct evidence is lacking as to whether or not these tumours were actively secreting prolactin. In the non-tumorous parts of the anterior lobes the number of prolactin cells was decreased in two cases, suggesting that prolactin released from the adenoma cells suppressed prolactin production in the non-tumorous pituitary. However, the number of prolactin cells of the non-tumorous adenohypophysis seemed to be unchanged in two and increased in another two cases. The present findings conclusively proved the existence of the prolactin-producing adenomas as a distinct entity. These tumours do not stain with acid or basic dyes, they are PAS or thionin negative, and do not contain immunoreactive growth hormone. Thus, by conventional staining procedures they are indistinguishable from other chromophobe adenoma types. Herlant's erythrosin and Brookes' carmoisine methods, claimed spedifically to stain prolactin cells, failed to provide reliable results, hence their use cannot be recommended in tumour identification. Immunoperoxidase staining of prolactin is the only technique which conclusively reveals the presence of immunoreactive prolactin in the cytoplasm of the tumour cells and permits diagnosis. It is proposed that this technique be introduced in pituitary morphological studies. Its application may lead to a better understanding of problems related to prolactin-producing tumours and their secretory activity.

Pure alpha subunit-secreting pituitary tumors.

The authors describe six patients with pituitary macroadenomas hypersecreting only the alpha subunit of the glycoprotein hormones. These patients had been previously diagnosed as having "non-functioning chromophobe adenomas." All of the patients had visual field abnormalities and partial hypopituitarism. The elevated serum alpha concentrations showed a variable response to stimulation by thyrotropin-releasing hormone, and could not be suppressed by thyroid hormone administration. Immunological, gel chromatographic, and immunocytochemical studies documented that only the alpha subunit was present. Following pituitary surgery and radiotherapy, serum alpha levels decreased. These patients represent a new subset of functioning pituitary tumors. Determination of alpha subunit concentration is useful in managing some patients with pituitary tumors previously thought to have non-functioning chromophobe adenomas.

Light and electron microscopical morphometry of pituitary adenomas in hyperprolactinemia.

Two highly differentiated acidophil prolactin-cell adenomas with hyperprolactinemia (group I), 8 large cell chromophobe adenomas with hyperprolactinemia (group II), and 2 small cell chromophobe adenomas (group III), one of which was combined with hyperprolactinemia, were studied immunohistologically. Morphometry was performed on the light- and electron microscopical level. The 11 active adenomas were immunohistologically positive for prolactin, the 12th adenoma with normal prolactin plasma level was negative for prolactin. Light microscopical morphometry displayed significantly more cells of smaller size in the "small cell chromophobe" adenomas, whereas the large cell chromophobe adenomas and the highly differentiated prolactin cell adenomas were not different. Ultrastructural morphometry demonstrated significant differences between highly differentiated prolactin cell adenomas (group I), and large cell chromophobe adenomas (group II). The latter contain smaller "relative volumes" of nucleoli and of secretory granules, whereas the rough endoplasmic reticulum, the Golgi fields and the nuclei were not different. Comparison of large cell chromophobe adenomas (group II), and small cell chromophobe adenomas (group III) revealed significantly larger relative volumes of nuclei and of mitochondria but smaller volumes of rough endoplasmic reticulum and of Golgi fields in the small cell chromophobe adenomas. Significant differences between the active and the inactive adenoma of small cell chromophobe type in the group III were not found. In spite of the low quantity of small cell chromophobe adenomas and of acidophil prolactin cell adenomas, our data demonstrate that there exist distinct and significant light microscopical and ultrastructural differences between the three adenoma types.(ABSTRACT TRUNCATED AT 250 WORDS)

Corticolipotropin immunoreactivity in silent chromophobe adenomas: a light and electron microscopic study.

Twenty silent human pituitary adenomas were morphologically studied. Immunoperoxidase methods showed numerous adrenocorticotropic hormone-immunoreactive tumor cells in 14 cases by light microscopy and in one additional case by electron microscopy. Three of these cases were positive for beta-endorphin and one for beta-lipotropin by electron microscopy. These immunoreactions were found in undifferentiated tumors as well as in oncocytic adenomas, and could not be related to the presence of basophils by light microscopy. The peptides so detected in silent adenomas may have no biological activity and may correspond to common precursor molecule subunits.

[Immunocytochemical similarities between basophilic and chromophobe pituitary adenomas. Light and electron microscopic study of 13 cases (author's transl)]. / Analogies immunocytochimiques des adénomes hypophysaires de la maladie de Cushing et des adénomes "non fonctionnels" (adénomes chromophobes) de l'hypophyse. A propos de 13 cas.

ACTH, beta MSH, beta LPH, beta endorpSin, leucine and methionine enkephalin activities were tested in four Cushing pituitary basophilic adenomas and nine "chromophobe" adenomas with immunoperoxidase methods. The antisera gave various positive reactions in both of these groups. ACTH, alpha MSH and enkephalins were predominant. The reason why these hormones are clinically silent in "chromophobe" or, even, basophilic adenomas is still to be elucidated.

Morphometric analysis of secretory granules and prolactin levels in chromophobe pituitary adenoma.

Morphometric analysis of secretory granules was performed in 16 chromophobe adenomas: seven undifferentiated cell adenomas (group A), two of which were accompanied by mild hyperprolactinemia and nine prolactin cell sparsely granulated adenomas (group B), all associated with hyperprolactinemia. The results of morphometry were correlated with levels of prolactin in tumor and serum. The range of granule diameters was similar in both groups but granule size frequency was different resulting in a characteristic histogram for each group. Poor relationship existed between granule mean diameter and prolactin in tissue of the group B. In the same group there was virtually no linear relationship between serum prolactin on one side and granule mean diameter, granule density or tissue prolactin on the other. Also in the group B a paradoxical inverse relationship was found between granule density and tumor prolactin. Apparently, in prolactin cell adenoma a sizable part of hormone is located outside of mature secretory granules. An abundance of immature granules, misplaced exocytosis, crinophagia or defect in packaging of the hormone could all explain this paradox but the last possibility seems most plausible.

Thyroid stimulating and gonadotrophic hormones in pituitary adenomas without clinical or serological abnormality.

Forty-three chromophobe adenomas have been examined immunocytochemically for their hormonal content. Twelve cases with full pre-operative normal serum hormonal levels were found to have many positive cells within the tumour for thyroid stimulating hormone (TSH), follicle stimulating hormone (FSH) and luteinizing hormone (LH). The specificity of the immunoreactive product within the tissue was checked by immunoabsorption. It is suggested that a non-secreted biologically inactive glycoprotein hormone is produced by tumour clones.

Pituitary Cushing's disease arising from a previously non-functional corticotrophic chromophobe adenoma.

Severe pituitary Cushing's disease of sudden onset after 18 years of unsuccessful treatment for a previously non-functioning chromophobe adenoma is described in a middle-aged woman. Initial presentation with symptoms of optic nerve compression had been preceded by two years of amenorrhoea. Transfrontal resection of a chromophobe adenoma followed by radiotherapy, performed both at this time and again after a recurrence eight years later, failed to eradicate the tumour. Ten more years elapsed before she rapidly developed florid features of Cushing's syndrome. Plasma ACTH levels were markedly elevated and were only partially reduced by further transfrontal surgery, complete removal of the tumour proving impossible. Subsequent bilateral adrenalectomy was performed to control her hypercortisolism and a course of cytotoxic chemotherapy was administered in an attempt to treat the tumour recurrence. Immunocytochemical staining of tumour obtained at surgery demonstrated ACTH immunoreactivity both before and after the development of Cushing's disease. Although silent corticotrophic adenomas of the human pituitary, including chromophobic tumours, have been previously described, this is the first report of such a tumour becoming functional, sufficient to cause clinically evident Cushing's disease.

Double tumors of anterior and posterior pituitary gland.

Double tumors were found in the anterior and posterior lobes of pituitary gland at autopsy in a patient who presented with progressive deterioration of mental status. The chromophobe adenoma of anterior lobe consisted of a mixture of non-immunoreactive hormone containing cells and a few prolactin (PRL) and growth hormone (GH) cells in the mid portion whereas the periphery of the tumor contained immunoreactive cells for PRL, GH, thyroid-stimulating hormone (TSH), luteinizing hormone (LH), and follicle-stimulating hormone (FSH). A microscopic focus of granular cell myoblastoma (GCM) was found in the posterior lobe. Differentiation of tumor cells into anterior pituitary cells and GCM is discussed.

A TSH secreting pituitary tumor accompanied by high stature: presentation of a case and review of the literature.

A 23-year-old man of high stature, with hypogonadism and bitemporal-upper-quadrant visual defects was found to have a pituitary tumor. He had a slightly enlarged struma, while he did not show any signs of hyperthyroidism. His serum TSH level (10.4 microunits/ml) was slightly elevated in spite of increased levels of serum thyroid hormone (T3 249 ng/dl, T4 12.0 microgram/dl). Neither the elevated serum TSH levels nor thyroidal uptake of 123I were suppressed after 7 days of 75 microgram triiodothyronine administration. Serum TSH levels did not increase further after TRH administration. Hypofunction of the anterior pituitary gland was observed. Following transsphenoidal hypophysectomy, his serum thyroid hormone and TSH levels returned to the normal range. Immunohistochemical examination revealed the existence of numerous TSH positive cells. From these data we concluded that the patient had a pituitary tumor which secreted inappropriate amounts of TSH.

Light microscopical morphometry, immunocytochemistry, and clinical correlations of pituitary adenomas at various stages of oncocytic transformation.

In a series of 124 pituitary adenomas displaying oncocytic alterations, we studied the degree of oncocytic transformation by light microcopical and morphometrical means for semiquantitative analysis. We established three groups with different percentages of oncocytically transformed cells for comparison of clinical and immunocytochemical data. Of the patients, 32.3% exposed adenomas with less than 50% oncocytic alterations (group I), whereas 22.6% showed tumours with oncocytic transformations between 51% and 75% (group II). Oncocytic parts consisting of more than 75% of the tumour cells were found in 41.1% of the patients (group III). All three groups differed in the rate of immunocytochemically positive cases, but not in sex distribution, tumour size, and rate of recurrency. Immunocytochemical analyses for PRL and GH (81 vs 78 adenomas) showed a decline of immunohistochemically positive adenomas with increasing proportions of oncocytic transformation for both hormones. Whereas in group I 38% of the adenomas were PRL-positive and 15% GH-positive, group III displayed only 9% PRL-positive and 3% GH-positive adenomas. The results display the correlation between the increasing volume of oncocytic transformation and its effect on decreasing hormone content in pituitary adenomas.