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Biomedical subjects

R V Randall

Publications and source records attributed to R V Randall.

At least 37 records · Page 2Linked to original sources

Pituitary gland in hypothyroidism. Histologic and immunocytologic study.

Primary hypothyroidism is associated with hypertrophy and hyperplasia of thyrotropic cells. In addition, pituitary adenomas that produce thyroid-stimulating hormone occur in both hypothyroidism and hyperthyroidism. The relationship between thyrotropic hyperplasia and adenoma formation is, however, unsettled. We summarize the results of a histologic and immunocytologic study of the pituitary glands of 64 patients with long-standing primary hypothyroidism in an effort to characterize the changes in thyrotropic cells as related to the duration and severity of disease, to therapy, and to the development of thyrotropic adenomas. Diffuse and nodular thyrotropic cell hyperplasia was noted in 69% and 25% of glands, respectively. A crude correlation was observed between the degree of thyrotropic cell hyperplasia and the relative lack of thyroid hormone replacement therapy. In 12% of glands, tumorlet formation was observed, perhaps representing an intermediate stage between nodular hyperplasia and the development of microadenoma. Twelve adenomas were noted, five of which contained thyroid-stimulating hormone immuno-reactive cells. Although thyroid hormone deficiency seemed to selectively affect thyrotropic cells, lactotropic hyperplasia was observed in 20% of patients; the mechanism accounting for prolactin cell hyperplasia remains obscure.

Adenoma↗

A case for hypothalamic acromegaly: a clinicopathological study of six patients with hypothalamic gangliocytomas producing growth hormone-releasing factor.

We report the histological, ultrastructural, and immunocytochemical features of six hypothalamic gangliocytomas associated with pituitary GH cell adenomas and/or acromegaly. In four patients, the gangliocytoma was intrasellar, and no hypothalamic investigation was performed; in two patients, autopsy confirmed hypothalamic involvement. Four patients had a gangliocytoma associated with pituitary GH cell adenoma and acromegaly; electron microscopy demonstrated an intimate association between neurons and adenomatous GH cells. One patient had a gangliocytoma and a GH cell adenoma but no clinical evidence of acromegaly. In the sixth patient, clinical and biochemical acromegaly was manifest, but no pituitary adenoma was demonstrated. Using immunocytochemistry, human pancreatic tumor GRF (hptGRF-40) was localized in the majority of neurons of all six gangliocytomas. The pituitary adenomas and nontumorous adenohypophyses were negative for hptGRF-40. In addition, somatostatin, glucagon, and GnRH were demonstrated within some neurons of several tumors; insulin and gastrin stains were equivocal. These findings confirm previous proposals of production of a GRF by such gangliocytomas. While the significance of other peptides found in some of the tumors is uncertain, the presence of hptGRF-40 in neurons of these gangliocytomas supports the theory that GRF excess is the mechanism responsible for over-production of GH and provides evidence for a syndrome of hypothalamic acromegaly.

Acromegaly↗

Demonstration of biological activity of prolactin molecular weight variants in human sera.

Three immunoreactive forms of PRL, separated by Sephadex G-100 column chromatography, were identified in serum samples from 10 normal subjects and 7 patients with PRL-secreting pituitary tumors. Fractions eluted from the column were assayed for bioactivity by using a sensitive bioassay with the Nb2 cell line. Three molecular weight variants of PRL were identified in normal subjects. In samples from 9 of the 10 normal subjects, 80.1 +/- 3.6% (mean +/- SEM) of the total bioactivity eluted in a peak corresponding to a PRL monomer (peak III) with a mol wt of approximately 24,000, 18.3 +/- 3.7% eluted in a peak with a mol wt of approximately 56,000 (peak II), and 1.6 +/- 1.1% of the biological activity was in the void volume (peak I). In the 10th normal sample, 65% of the total bioactivity was in the void volume (peak I), 31% was in peak III, and 4% was in peak II. Samples from the patients had 3.6 +/- 0.7% of the total bioactivity in peak I, 9.3 +/- 1.0% in peak II, and 87.0 +/- 1.1% in peak III, percentages not significantly different from normal. For comparison with bioassay, RIA measurement of PRL was performed on all fractions of six samples (three normal subjects and three tumor patients). Good correlation was found between RIA and bioassay measurements under each of the three peaks identified. We conclude that 1) in sera from normal subjects, three molecular weight variants of PRL have biological activity; 2) in patients with PRL-secreting tumors, secretion of biologically active PRL molecular weight variants is not proportionately different from that in normal subjects; and 3) the results of the Nb2 PRL bioassay correlate well with PRL levels determined by RIA for each of three molecular weight variants identified.

Adenoma↗

Empty sella syndrome.

Awareness of the entities of primary and secondary empty sella syndrome and the use of current CT scanning techniques should allow one to differentiate between these conditions and persistent or recurrent pituitary adenoma. This distinction is important to make so unwarranted surgery or radiation therapy will not be advised.

Adenoma↗

Pregnancy following transsphenoidal resection of prolactin-secreting pituitary tumors.

This report describes 200 women in the childbearing age group with prolactin-secreting pituitary adenomas treated by transsphenoidal microsurgery. There were 136 patients with microadenomas (10 mm or less in diameter), 30 with macroadenomas, 11 with invasive adenomas, and one with hyperplasia. The overall rate for postoperative normalization of serum prolactin was 57%, and it was 72% for those patients with microadenomas. Pregnancy was desired by 90 women, and 78 (84%) became pregnant, although 10 required postoperative bromocriptine to do so. Serious postoperative complications were rare, and produced no major morbidity. The results of surgery were most favorable in women with microadenomas and preoperative serum prolactin levels of 100 ng/ml or less.

Adenoma↗

The pituitary gland in untreated Addison's disease. A histologic and immunocytologic study of 18 adenohypophyses.

The pituitary glands of 18 patients with untreated Addison's disease were studied by histologic and immunocytochemical methods. Adrenal destruction was caused by tuberculosis (13 cases) or autoimmune adrenalitis (five cases), and the duration of the adrenal insufficiency ranged from one to 16 years. Both diffuse and nodular hyperplasia of corticotropic cells were evident in each case, and the extent of hyperplasia correlated with the duration of disease. In five cases, nodular proliferations with morphologic features between those of hyperplasia and those of adenoma, termed tumorlets, were identified, as were two microadenomas, only one of which was available for study. In all instances, the proliferating corticotrophs stained positively with PAS and were immunoreactive for adrenocorticotropic hormone and beta-endorphin. We conclude that diffuse and nodular corticotroph hyperplasia are common in untreated Addison's disease, although frank adenoma formation seems to be rare. The latter may be related to the short duration of disease or may imply the absence of additional, unknown factors that are required for adenoma growth.

Addison Disease↗

Hypothalamic neuronal hamartoma and adenohypophyseal neuronal choristoma: their association with growth hormone adenoma of the pituitary gland.

Hypothalamic neuronal hamartomas and neuronal choristomas of the anterior pituitary are rare lesions; either may be associated with endocrinopathy. We describe a case of each with associated growth hormone-producing pituitary adenomas and clinical acromegaly, both well documented and studied by immunocytochemistry and electron microscopy. That a functional relationship exists between the neuronal malformation and the pituitary neoplasm remains speculative. We suggest that a growth hormone-releasing factor-like substance may have been elaborated by hypothalamic-type neurons, which, by a trophic effect, may have resulted in the production of an adenohypophyseal neoplasm. Our study supports the concept that secretory neurons, either outside or within the sella, may induce adenomas.

Acromegaly↗

Transsphenoidal microsurgical treatment of prolactin-producing pituitary adenomas. Results in 100 patients.

One hundred patients, 84 females and 16 males, with presumed prolactin-producing pituitary adenomas were treated with transsphenoidal microsurgery. Criteria for success of the operation were return of serum prolactin values to normal and reversal of the endocrine effects of hyperprolactinemia, eradication of the adenoma, and preservation of anterior pituitary function. Of the 84 females, 54 had a microadenoma (a noninvasive adenoma 10 mm or less in diameter), and of the 32 with preoperative values of serum prolactin of less than 100 ng/ml, 28 (88%) had a successful operative result, whereas 11 of 22 (50%) with preoperative values of 100 ng/ml or more had a successful result. Five of 10 patients (50%) with a diffuse adenoma (a noninvasive adenoma more than 10 mm in diameter) and 5 of 20 (25%) with an invasive adenoma had a successful result. Of the 16 males, 3 of 7 (43%) with diffuse adenoma and 3 of 16 (19%) with invasive adenoma had a successful result. There were no males with microadenoma. The largest success rate (88%) was among female patients with microadenoma and preoperative serum prolactin values of less than 100 ng/ml.

Adenoma↗

Coexistent primary empty sella syndrome and hyperprolactinemia. Report of 11 cases.

The series involved 11 women with concurrent hyperprolactinemia and primary empty sella syndrome. Eight had amenorrhea and six had galactorrhea. All 11 patients had intact hypothalamic-pituitary function, except for having elevated prolactin levels that ranged from 33 to 498 ng/mL. One patient had primary hypothyroidism. Radiologic investigations included sellar polytomography in eight cases, computed tomography of the head in eight cases, bilateral carotid angiography in six cases, and pneumoencephalography in three cases. Of eight patients undergoing transsphenoidal exploratory surgery, one had a pituitary microadenoma and an empty sella while seven had only an empty sella with a flattened pituitary gland. Conventional histologic methods (seven cases) and immunocytologic studies (three cases) of the pituitary gland showed no abnormalities. The cause of this syndrome is unknown. It should be recognized that hyperprolactinemia, with or without galactorrhea-amenorrhea, may occur in association with an empty sella in the absence of an associated pituitary tumor.

Adult↗

Primary amenorrhea and pituitary adenomas.

From 1972 to 1980, 210 patients underwent transsphenoidal operation for removal of a prolactin-secreting tumor. Eight of the patients had primary amenorrhea. All eight patients had had a normal thelarche and pubarche without menarche, and all eight had hyperprolactinemia and abnormal findings on sella turcica tomography. After operation, only one patient did not have persistent hyperprolactinemia, and this patient was the only one who began spontaneous menses. The data indicate that although prolactin hypersecretion interferes with menstrual function, it does not alter other pubertal development and that, if the source of the excessive prolactin can be removed, the removal alone may initiate spontaneous menses. In this report, however, patients with prolactin-secreting adenomas and primary amenorrhea had a high incidence of persistent hyperprolactinemia after operation (seven of eight patients).

Adenoma↗