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S Marcovitz

Publications and source records attributed to S Marcovitz.

10 recordsLinked to original sources
PubMed1987

The diagnostic accuracy of preoperative CT scanning in the evaluation of pituitary ACTH-secreting adenomas.

Between 1980 and 1985, 35 patients (26 women and nine men) who had coronal CT scans of the sella turcica for suspected ACTH-secreting pituitary adenoma underwent transsphenoidal exploration. The CT examinations were performed with a fourth-generation EMI scanner (CT 7070). The reports of the preoperative CT examinations were compared with the findings at transsphenoidal exploration; in cases with negative CT scans, the decision to operate was based on biochemical evidence of Cushing's disease. In 27 patients, distinct adenomas were found at surgery; in the eight others, total hypophysectomy (four cases) or resection of the central core of the pituitary gland (four cases) was performed. Three patients had macroadenomas, all of which had been identified correctly on preoperative CT scan. Among the 24 microadenomas (less than 10 mm diameter), 14 had been correctly identified on preoperative CT scan while 10 were found in patients with negative scans. The CT examinations in these 35 patients showed probable adenomas in 20 cases, of which 17 (85%) were confirmed at surgery. In the other three cases (15%), adenomas were not found. Among the 15 patients with negative CT scans, 10 (66.6%) had distinct adenomas found at surgery. Coronal CT scans for ACTH-secreting adenomas had a sensitivity of 63%, a specificity of 62.5%, and an overall accuracy rate of 62.8%. Thus, in our experience, CT scanning with current state-of-the-art equipment has poor diagnostic accuracy in Cushing's disease. The possible reasons for this are that most of the adenomas in this series were microadenomas less than 6 mm in diameter, and that ACTH microadenomas probably show almost the same degree of enhancement with contrast medium as the surrounding normal pituitary tissue.

Adenoma↗
PubMed1986

Effect of insulin-like growth factors on human foetal, adult normal and tumour pituitary function in tissue culture.

To determine the direct effects of insulin-like growth factors (IGFs) on hormone release by the human pituitary gland, human foetal, adult normal and tumour pituitary tissues were maintained in culture for 2 to 4 weeks and tested with acute (3 h) exposures to different preparations of IGF peptides. Adult normal pituitaries and adenomas were tested with a semipurified preparation of IGFs, free of immunoreactive insulin, containing IGF-I and IGF-II in a ratio of approximately 1:4. Human foetal pituitaries were tested with the semipurified IGFs as well as more purified preparations of IGF-I and IGF-II. Culture media were assayed for hGH, hPrl, hACTH and hLH using specific radioimmunoassays. Both foetal (n = 16 (No. of pituitaries), 33 (No. of observations] and normal adult (n = 3, 16) human pituitaries cultures responded to the semipurified IGFs (2-25 ngEq/ml for foetal and 2-4 ngEq/ml for adult pituitaries) with a significant decrease in hGH release compared to basal (P less than 0.01) whereas the GH-secreting pituitary tumours showed no effect when tested with from 2 to 25 ngEq/ml (n = 8, 129, NS). The effect of IGFs on human foetal somatotrope activity was dose-related for both the semipurified IGFs (2-25 ngEq/ml, n = 16, 33) and IGF-I or IGF-II (10-100 ng/ml; n = 3, 18).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1984

Intrasellar germinoma associated with hyperprolactinemia.

We report two young adult patients with hyperprolactinemia and neuroendocrine deficits due to predominantly intrasellar germinomas. In both cases the diagnosis of germinoma was confirmed histologically after transsphenoidal surgery. This very rare type of tumor may be intrasellar and it may mimic prolactinoma or craniopharyngioma. Dynamic testing of pituitary function and computed tomography scanning are of value in the early detection of this malignant but radiocurable lesion.

Adult↗
PubMed1983

Pituitary tumors and the ophthalmologist.

The authors examined 200 consecutive patients with pituitary adenomas admitted to the neuroendocrine service at the Montreal General Hospital between 1976 and 1981. The main presenting signs and symptoms were amenorrhea/impotence (70%), headache (46%), and typical acromegalic or cushingoid features (28%). Only 9% had visual field defects, 2% had optic atrophy, and 1% had ocular motility problems. A comparison of our findings with four previous studies has demonstrated an increasing incidence of reproductive system abnormalities and a decreasing incidence of visual abnormalities in patients with pituitary tumor. The reasons for this changing pattern are discussed and the role of the ophthalmologist in the care of these patients is redefined.

Acromegaly↗
PubMed1980

Hyperthyroidism due to a pituitary TSH secreting tumour with amenorrhoea-galactorrhoea.

A 20-year-old female presented with thyrotoxicosis associated with amenorrhoea and galactorrhoea after oral contraceptive withdrawal. Serum TSH was persistently elevated (mean: 28 +/- 3.1 microU/ml during 24-h sampling and did not vary significantly after TRH, bromocriptine or somatostatin. Prolactin levels remained constantly at the upper limit of normal (mean: 20.6 +/- 2.1 ng/ml, with a minimal increase after TRH, a slight decrease after somatostatin (54%) and a marked decrease after bromocriptine (88.5%). Surgical exploration revealed an unusually firm tumour adherant to the wall of the sella turcia; electron microscopic study showed that it was composed almost exclusively of thyrotrophs. After a transient period of euthyroidism post-operatively, T3 toxicosis occurred with an increased TSH level (15.5 microU/ml) and a rise in TSH and alpha subunit in response to TRH. An increase in T4 followed while prolactin remained low.

Adult↗
PubMed1977

Coexisting primary empty sella syndrome and acromegally.

The 'empty' sells syndrome is now a more frequent diagnosis due to the increased use of pneumoencephalography in the evaluation of the enlarged pituitary fossa. This syndrome has also been classified into a 'primary' form in which there has been no prior pituitary irradiation or surgery, and a 'secondary' form in which the empty sella is found after such procedures. Most patients with the primary empty sella syndrome are found to have normal pituitary function while about 30% have varying degrees of hypopituitarism (Neelon et al., 1973). It is not widely appreciated, however, that the primary empty sella may harbour a pituitary tumour with resultant acromegaly. In this report we describe two such patients who presented with active acromegaly. This entity of pituitary tumour in a primary empty sella merits careful consideration since the coexistence of these two findings may influence the therapeutic approach that might otherwise be appropriate for the pituitary tumour.

Acromegaly↗
PubMedDate not supplied

Diagnostic accuracy of preoperative CT scanning of pituitary prolactinomas.

Between 1980 and 1985, 102 patients (84 women and 18 men) who had coronal CT scans of the sella turcica for suspected prolactin adenoma underwent transsphenoidal exploration. The CT examinations were performed with a fourth-generation EMI scanner (CT 7070), and reports of the preoperative CT examinations were compared with the findings at transsphenoidal exploration. The same neurosurgeon performed all the operations. In 97 patients distinct adenomas were found at surgery, among which were 36 macroadenomas (diameter larger than 10 mm) and 62 microadenomas (one patient had two coexisting microadenomas). All macroadenomas were identified correctly on the preoperative CT scans. Preoperative CT scans correctly localized 58 microadenomas in 57 of 62 patients, for a sensitivity rate of 91.9%; this included correct localization in four patients with recurrent microprolactinomas and in the one patient with two coexisting adenomas. Three patients in whom the adenomas were found in a location other than that reported on the preoperative CT scan were considered to have false-negative scans for the purpose of statistical calculations; two other false negatives occurred in patients whose scans had been interpreted as entirely normal and who were subsequently found to have adenomas at operation. Four patients had negative surgical explorations and the preoperative CT scan was correct in one, for a specificity of 25%. The overall accuracy rate was 92.1% for the entire group of patients and 87.7% for the subgroup of microadenomas. In our experience, coronal CT scanning has high diagnostic accuracy in patients with pituitary prolactinomas.

Adenoma↗
PubMedDate not supplied

Diagnostic accuracy of preoperative CT scanning of pituitary somatotroph adenomas.

Between 1980 and 1986, 58 patients (23 women and 35 men) had coronal CT scans of the sella turcica for suspected growth hormone-secreting adenoma and underwent transsphenoidal exploration. The CT examinations were performed with a fourth-generation EMI scanner (CT 7070), and reports of the preoperative CT were compared with the findings at transsphenoidal exploration. The same neurosurgeon performed all the operations. In three patients arthritic changes in the neck caused difficulties in positioning, which made it impossible to obtain adequate coronal CT scans. These nondiagnostic examinations are excluded from the statistical calculations. In all 55 patients with scans that were able to be evaluated, distinct adenomas were found at surgery. Among these were 39 macroadenomas (diameter larger than 10 mm) and 16 microadenomas. Three macroadenomas and two microadenomas caused combined hypersecretion of growth hormone and prolactin. All macroadenomas were localized correctly on the preoperative CT scans (sensitivity 100%), but in two cases there was a discrepancy in size of more than 5 mm compared with the operative findings. Preoperative CT scans correctly localized 13 of 16 microadenomas, for a sensitivity rate of 81.2%. Two patients with negative scans and one patient in whom the adenoma was found in a location other than that reported on the preoperative CT scan were considered to have negative scans for the purpose of statistical calculations. If both correct localization and size estimation within 2 mm of that found at surgery are considered, the accuracy rate was 90.9% for the entire group of patients, 94.9% for those with macroadenomas, and 81.2% for microadenomas.

Adenoma↗