PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “ADRENAL GLAND NEOPLASMS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources

Adrenal adenomas: characteristic hyperintense rim sign on fat-saturated spin-echo MR images.

PURPOSE: To determine whether adrenal adenomas can be differentiated from metastases on fat-saturated magnetic resonance (MR) images. MATERIALS AND METHODS: Twenty-eight adrenal adenomas and 20 metastatic lesions were imaged at 1.5 T by means of fat-saturated T1- and T2-weighted and gadolinium-enhanced T1-weighted sequences. The authors evaluated visually whether structures of high signal intensity (hyperintense rim sign) could be observed in the outer margin of the adrenal masses. RESULTS: Twenty-six of 28 adrenal adenomas revealed the hyperintense rim sign on at least one kind of fat-saturated image, compared with only one of 20 metastases. The sensitivity of the hyperintense rim sign as suggestive of adrenal adenoma was 92%, specificity was 95%, and overall accuracy was 94%. CONCLUSION: The hyperintense rim sign is characteristic of adrenal adenomas. Thus, adrenal adenomas can be differentiated from metastases by means of this new imaging sign on fat-saturated MR images.

Adrenal Cortex Neoplasms↗

Dual sites of inhibition by metyrapone of human adrenal steroidogenesis: correlation of in vivo and in vitro studies.

In a patient with pituitary ACTH-dependent adrenal hyperplasia (AH), the standard oral metyrapone test resulted in a decrease in "apparent 11beta-hydroxylase activity" (-48%) accompanied by an increase in "apparent cholesterol cleavage activity" (+318%). When incubated adrenal mitochondria from this patient were studied, metyrapone inhibited both 11beta-hydroxylation of labeled 11-deoxycorticosterone and cleavage of labeled cholesterol, although at 0.1 and 1.0 mM metyrapone concentrations, depression of cholesterol cleavage (23 and 54%, respectively) was less than that of 11beta-hydroxylation (62 and 84%, respectively). The inhibition of cholesterol cleavage by metyrapone (26 and 62%, at 0.1 and 1.0 mM concentrations, respectively) was also demonstrable in adrenal mitochondria from a patient with hypercorticism resulting from an ACTH-independent adrenal adenoman (AA). Metyrapone administration to AA resulted in a significant depression of both 11beta-hydroxylase (-62%) and cholesterol cleavage (-36%) "apparent activities"; when metyrapone and ACTH were given together to this patient, however, only 11beta-hydroxylase "apparent activity" diminished (-26%), while cholesterol cleavage "apparent activity" was greatly augmented (+231%), thereby simulating the results of the standard metyrapone test in AH. These data demonstrate that metyrapone inhibits both mitochondrial reactions involved in cortisol synthesis--initial cholesterol cleavage and final 11beta-hydroxylation; these effects probably result from interference by this agent with the interaction between substrate and related cytochrome P - 450. Since ACTH has a major stimulatory effect on cholesterol cleavage but not on 11beta-hydroxylation, the outcome of metyrapone administration is thus determined by whether a change in ACTH level ensues: while 11beta-hydroxylation is inhibited by metyrapone under any circumstances, total steroid output rises when a compensatory ACTH increase overcomes metyrapone inhibition of cholesterol conversion into pregnenolone and falls when metyrapone inhibition of this reaction is unopposed.

Adenoma↗

[Image diagnosis of adrenal disorders. III. "Nonfunctioning" adrenal adenoma, weak mineralocorticoids producing adrenal carcinoma, congenital adrenogenital syndrome due to 21-hydroxylase deficiency--simple virilizing form, and pheochromocytoma].

The image diagnoses of a case of so-called "nonfunctioning" adrenal adenoma, weak mineralocorticoids producing adrenal carcinoma, congenital adrenogenital syndrome due to 21-hydroxylase deficiency--simple virilizing form--, and 5 cases of pheochromocytoma were studied. In a patient with so-called "nonfunctioning" adrenal adenoma (2.3 X 3.0 X 3.3 cm), in which steroids biosynthesis was confirmed, computed tomography (CT) delineated the tumor shadow with extremely low density, and ultrasonography (US) demonstrated the round tumor echo with homogenous and low echogenicity at the superior region of the right renal pole. Adrenal scintigraphy also showed the tumor image. A weak mineralocorticoids-producing left adrenal carcinoma (3.5 X 3.5 X 3.0 cm) was shown as a heterogenous round tumor at the left lateral portion of the vertebra by CT. On adrenal scintigraphy under dexamethasone pretreatment, there was good uptake in the tumor and disappearance of the contralateral. Both bilateral adrenal images on CT in a patient with congenital adrenogenital syndrome were linear-shaped and markedly enlarged. The enlarged right adrenal was clearly demonstrated by US with an electronic sector scanner but not with an electronic linear scanner, although the left one was hardly shown by either US instruments. Three of 4 patients with pheochromocytomas examined by US were correctly detected, while in the remaining one the tumor image was judged to be a retroperitoneal tumor. CT also correctly demonstrated the former 3 pheochromocytomas, but misjudged the latter one as a pancreatic cancer. Good uptake of Adosterol by bilateral adrenals was shown in a case of extra-adrenal pheochromocytoma. Three of 4 cases of adrenal pheochromocytoma showed the isotope uptake of the contralateral normal adrenal alone. In another case of right adrenal pheochromocytoma, isotope accumulation in the colon obscured whether the isotope uptake in the right adrenal was shown or not.

Adenoma↗

Expression patterns of the c-myc gene in adrenocortical tumors and pheochromocytomas.

Abundant c-myc gene expression in neoplasms has been often linked to poor prognosis. As c-myc mRNA is expressed and hormonally regulated in human adrenals, we examined the c-myc gene expression in adrenal tumors by RNA analysis and immunohistochemistry to find out the possible role of c-myc in adrenal neoplasms. The abundant expression of the c-myc gene in normal adrenals was localized to the zona fasciculata and zona reticularis, with much lower expression in the zona glomerulosa and adrenal medulla. In hormonally active adrenocortical carcinomas (n = 6) and in virilizing adenomas (n = 4), c-myc mRNA levels were approximately 10% of those in normal adrenals (n = 11). In contrast, adrenal adenomas from patients with Cushing's (n = 4) and Conn's (n = 9) syndrome, non-functional adenomas (n = 2), adrenocortical hyperplasias (bilateral, n = 5; nodular, n = 4), and non-functional adrenocortical carcinomas (n = 3) expressed c-myc mRNA to the same extent as normal adrenals. The c-myc mRNA abundance in benign adrenal pheochromocytomas (n = 19) was similar to that in normal adrenal medulla. However, in malignant adrenal pheochromocytomas (n = 6), the average c-myc mRNA levels were approximately threefold that in benign adrenal pheochromocytomas. There was a good correlation between c-myc mRNA expression and immunohistochemical reactivity in both normal and pathological adrenal tissues. Southern blot analysis revealed no amplification or rearrangement of the c-myc gene in any of the adrenal tumors. In conclusion, c-myc expression localized to zona fasciculata and reticularis in normal adrenals. Virilizing adenomas and hormonally active adrenocortical carcinomas expressed c-myc mRNA clearly less than the other adrenal neoplasms and normal adrenal tissue. On the other hand, malignant pheochromocytomas contained more c-myc mRNA than benign ones. Further studies are required to clarify the mechanisms and significance for the distinct expression pattern of the c-myc gene in different adrenal neoplasms.

Adrenal Cortex Neoplasms↗

Comparison of two algorithms and their associated charges when evaluating adrenal masses in patients with malignancies.

OBJECTIVE: This study was performed to compare two proposed algorithms used when evaluating an adrenal mass discovered during staging evaluation of a patient with a known malignancy. Such evaluation was meant to lead to determination of the relative charges associated with each algorithm. SUBJECTS AND METHODS: Fifty-four patients with known malignancies who required evaluation of an adrenal mass underwent both chemical shift imaging (CSI) and CT-guided for CSI. The hospital charges incurred for each procedure and any associated complications were normalized using national relative-value scale charges and conversion factors. A decision analysis was performed to compare the relative charges that would have been incurred if adrenal MR imaging had been performed in all patients, followed by CT-guided biopsy only in those patients with MR findings not diagnostic of adrenocortical adenoma, and the relative charges incurred if only CT-guided adrenal biopsy had been performed in every patient. RESULTS: Twenty-three (43%) of 54 adrenal masses were shown to be metastases by CT-guided biopsy. The sensitivity and specificity of CSI for the diagnosis of adrenocortical adenoma were 94% and 100%, respectively. The charges incurred by performing MR imaging as the initial examination with subsequent CT-guided biopsy only in those patients with CSI findings not diagnostic of adenoma would have been similar to those incurred by first performing CT-guided adrenal biopsy in every patient. CONCLUSION: CSI is an accurate, noninvasive technique for evaluating adrenal masses in patients with cancer. If CT-guided biopsy is used only when CSI is not diagnostic of adrenocortical adenoma, the associated charges would be virtually the same as when CT-guided biopsy is performed as the first test in every patient. Moreover, biopsies could have been avoided in 54% of these patients.

Adrenal Cortex Neoplasms↗

Characterization of adrenal masses using MR imaging with histopathologic correlation.

OBJECTIVE: The purpose of this study was to evaluate the sensitivity, specificity, and accuracy of MR imaging in the characterization of adrenal masses by correlating imaging findings with histopathologic results. In addition, adrenal tumors that were of an indeterminate nature on MR imaging were analyzed. SUBJECTS AND METHODS: For 114 patients with 134 adrenal masses, MR findings were compared with histologic results. In all patients, MR imaging was performed using T2-weighted fast spin-echo imaging and unenhanced and gadolinium-enhanced T1-weighted spin-echo imaging. Chemical-shift imaging was performed in 92 patients and dynamic gadolinium-enhanced studies in 108 patients. Chemical-shift images were analyzed quantitatively and qualitatively, and dynamic gadolinium-enhanced studies were qualitatively assessed. RESULTS: The sensitivity of MR imaging in differentiating between benign and malignant adrenal masses was 91%, the specificity was 94%, and the accuracy was 93%. The diagnosis at MR imaging differed from that at histology in 12 (9%) of 134 patients. Results of quantitative analyses of chemical-shift imaging techniques showed significant differences between adenomas and nonadenomas (-36.0% versus -3.7%; p < .001). Qualitative analysis provided a similar diagnostic confidence compared with quantitative analysis. Both chemical-shift and dynamic gadolinium-enhanced studies proved to be unreliable in characterizing borderline tumors (epithelial tumors with high malignant potential). Moreover, such imaging failed to allow correct diagnosis of adenomas in two patients. CONCLUSION: The characterization of an adrenal mass can be made with high sensitivity and specificity using MR imaging. The increased reliance on MR imaging seems to be based mainly on findings from chemical-shift and dynamic gadolinium-enhanced studies. The need to perform histologic sampling of incidentally discovered adrenal masses may be reduced to some problematic lesions, which will remain during the era of MR imaging.

Adolescent↗

Differential expression of prolactin receptor (PRLR) in normal and tumorous adrenal tissues: separation of cellular endocrine compartments by laser capture microdissection (LCM).

PRL stimulates adrenal steroidogenesis. In this study, we compared the PRLR expression in normal and tumorous adrenal tissues and investigated a potential proliferative effect of PRL in adrenal cells. mRNA expression of long and intermediate forms of PRLR was detected in both normal adrenal cortex as well as benign and malignant adrenal tumors and in the human adrenocortical carcinoma cell line NCI-H295. Molecular analysis of cells procured by LCM clearly demonstrated that PRLR mRNA is expressed in the adrenal cortex but not in the medulla. Immunostaining revealed PRLR protein in all three zones of the normal adrenal cortex. Furthermore, adrenal carcinomas and adenomas stained positive for the PRLR, while in phaeochromocytomas as in the normal adrenal medulla, no specific staining was observed. By WST-1 test, we could show that PRL (10(-7) M) decreased proliferation and viability of adrenal cells in primary cell culture suggesting that PRL is not a mitogenic factor of adrenocortical cells.

Adrenal Cortex↗

[Clinical evaluation of scintigraphy and tumor biopsy for incidentally detected adrenal masses].

PURPOSE: A decision tree in diagnosis of incidentally detected adrenal masses (incidentaloma) was made on the basis of these results. METHODS: The clinical usefulness of adrenal scintigraphy with 131I-adosterol and ultrasonically guided tumor biopsy was investigated in 44 patients. RESULTS: Adrenal scintigraphy was performed in 32 patients, of whom 21 were found to have an increased uptake in the tumor, including 19 cases of cortical adenoma and 2 of hematoma. No abnormal uptake was found in the remaining 11 patients, including 2 of cortical adenoma, 1 of adrenocortical oncocytoma and 8 of non-cortical tumors. Adrenal scintigraphy was thus thought to be useful in the differentiation of cortical tumor from non-cortical tumor, showing the sensitivity of 86%, the specificity of 80% and the diagnostic accuracy of 84%. Cytological or histological study on specimens obtained by percutaneous adrenal tumor biopsy was performed in 19 patients, of whom 18 (95%) were correctly diagnosed in terms of the malignancy of incidentaloma. CONCLUSIONS: Taken together, the differential diagnosis and the surgical indication of adrenal incidentaloma could be made successfully based on adrenal scintigraphy and tumor biopsy.

Adenoma↗

MR imaging of the adrenal neoplasms.

The most commonly encountered adrenal mass is the non-hyperfunctioning adrenal adenoma. Chemical-shift MR imaging can detect and characterize these adrenal masses as benign but cannot distinguish between hypersecreting and nonhypersecreting adrenal adenomas. Because of its direct multiplanar capability and superb soft tissue contrast, MR imaging can detect and potentially characterize other adrenal neoplasms.

Adrenal Cortex Neoplasms↗