Syndrome of resistance to thyroid hormone and thyrotropin-secreting pituitary adenoma: Case series study / 中华内分泌代谢杂志

Objective:To outline clinical features in syndrome of resistance to thyroid hormone(RTH) and thyrotropin-secreting pituitary adenoma(TSH adenoma) based on a case series, and to assess the value of octreotide suppression test and high-dose dexamethasone suppression test(HDDST) in differentiating the two diseases.Methods:A total of 22 cases with RTH and TSH adenoma clinically diagnosed in Xiangya Hospital of Central South University from October 2010 to December 2021 were retrieved. The clinical characteristics of the two diseases and results to different tests were analyzed and summarized.Results:(1) The tumors in TSH adenoma patients were larger than those with RTH complicated with pituitary mass, which presented chiasmatic compression on images( P<0.05). (2) In octreotide suppression test, thyrotropin(TSH) inhibition rate in RTH patients was lower than that in TSH adenoma patients( P<0.05). In HDDST, TSH inhibition rate was higher in patients with RTH than in patients with TSH adenoma( P<0.05). (3) The TSH inhibition rate was calculated by receiver operating characteristic(ROC) curve. The sensitivity and specificity of octreotide suppression test were 91.9% and 55.6%, respectively, and the threshold value of TSH inhibition rate was 64.24%. The sensitivity and specificity of HDDST were 54.4% and 89.0%, respectively, and the threshold value of TSH inhibition rate was 65.73%.The combined sensitivity and specificity of the two tests were 77.8% and 90.9%, indicating better diagnostic value( P<0.05). Conclusions:The combination of octreotide suppression test and HDDST is of clinical value in differentiating RTH from TSH adenoma. TSH adenoma is more aggressive than that of pituitary adenoma with RTH.

Limited Diagnostic Utility of Plasma Adrenocorticotropic Hormone for Differentiation between Adrenal Cushing Syndrome and Cushing Disease

BACKGROUND: Measurement of the plasma adrenocorticotropic hormone (ACTH) level has been recommended as the first diagnostic test for differentiating between ACTH-independent Cushing syndrome (CS) and ACTH-dependent CS. When plasma ACTH values are inconclusive, a differential diagnosis of CS can be made based upon measurement of the serum dehydroepiandrosterone sulfate (DHEA-S) level and results of the high-dose dexamethasone suppression test (HDST). The aim of this study was to assess the utility of plasma ACTH to differentiate adrenal CS from Cushing' disease (CD) and compare it with that of the HDST results and serum DHEA-S level. METHODS: We performed a retrospective, multicenter study from January 2000 to May 2012 involving 92 patients with endogenous CS. The levels of plasma ACTH, serum cortisol, 24-hour urine free cortisol (UFC) after the HDST, and serum DHEA-S were measured. RESULTS: Fifty-seven patients had adrenal CS and 35 patients had CD. The area under the curve of plasma ACTH, serum DHEA-S, percentage suppression of serum cortisol, and UFC after HDST were 0.954, 0.841, 0.950, and 0.997, respectively (all P<0.001). The cut-off values for plasma ACTH, percentage suppression of serum cortisol, and UFC after HDST were 5.3 pmol/L, 33.3%, and 61.6%, respectively. The sensitivity and specificity of plasma ACTH measurement were 84.2% and 94.3%, those of serum cortisol were 95.8% and 90.6%, and those of UFC after the HDST were 97.9% and 96.7%, respectively. CONCLUSION: Significant overlap in plasma ACTH levels was seen between patients with adrenal CS and those with CD. The HDST may be useful in differentiating between these forms of the disease, especially when the plasma ACTH level alone is not conclusive.

Relationship between low- and high-dose dexamethasone suppression test in patients with Cushing syndrome / 中华内分泌代谢杂志

Objective To investigate the relationship between the degree of serum cortisol suppression by low-dose dexamethasone (1 mg) and full serum cortisol suppression (suppression rate > 50% ) by high-dose dexamethasone (8 mg) in patients with Cushing syndrome, and to evaluate these tests in Cushing disease. Methods Ninty-one patients with Cushing syndrome were studied retrospectively. The relationship of 20%, 30%, 40%, and 50% cortisol suppression by overnight 1mg dexamethasone with full serum cortisol suppression by overnight 8 mg dexamethasone was analyzed, and the sensitivity and specificity in the diagnosis of Cushing disease were evaluated. Results The degree of cortisel suppression during overnight 1 mg dexamethasone suppression test was correlated with that during overnight 8 mg dexamethasone suppression test (r=0. 649,P<0. 001 ). 30, 22, 13, and 9 patients had greater than 20%, 30%, 40%, and 50% serum cortisol suppression respectively during overnight 1 mg dexamethasone suppression test. Among them, 23 ( 76. 7% ), 20 (90. 9% ), 12 (92.3%), and 9 ( 100.0% )patients had full serum cortisol suppression during overnight 8 mg dexamethasone suppression test. The sensitivity of the cutoff of greater than 20%, 30%, 40%, and 50% serum cortisol suppression for the diagnosis of Cushing disease was 52.8%, 32.7%, 22.6%, and 15.7%, and the specificity was 94.7%, 94.7%, 97.4%, and 97.4% respectively. Conclusions In patients with Cushing syndrome, greater than 20% serum cortisol suppression during overnight 1 mg dexamethasone suppression test is usually associated with full serum cortisol suppression during overnight 8 mg dexamethasone suppression test, and most of them are finally diagnosed as Cushing disease.

A Case of Bilateral Macronodular Adrenal Hyperplasia with Cushing's Syndrome Treated by Unilateral Adrenalectomy / 대한내분비학회지

In order to differentiate the causes of Cushing's syndrome; whether it is pituitary or adrenal-dependent, a high dose dexamethasone suppression test is usually performed but this does not always correlated with the imaging diagnosis. We report a case of bilateral macronodular adrenal hyperplasia, which was thought to be independent to adrenocorticotrophin (ACTH) stimulation. At first we thought it was pituitary-dependent Cushing's syndrome, due to its suppression by high dose dexamethasone. However, we found no abnormal findings on the brain sella magnetic resonance image (MRI). A significant finding, however, we found bilateral adrenal masses on the abdominal computed tomography (CT). We performed percutaneous selective adrenal venous sampling (PSAVS), and confirmed hypercortisolism of the left adrenal mass only. Therefore, we decided to remove the left adrenal gland to preserve the residual function of the right adrenal gland. After the left adrenalectomy, the patient became normotensive, and their buffalo hump disappeared, and her 24 hour urinary free cortisol level returned to normal.

High-dose dexamethasone suppression test-related differences in the clinical and biochemical features of Cushing's disease / 中华内分泌代谢杂志

Objective To analyse the high-dose dexamethasone suppression test(HDDST)-related differences in the clinical and biochemical features of the patients with Cushing's disease Methods Cases were drawn from 60 consecutive patients with Cushing's disease,who were then divided into two groups according to the response to the HDDST.The clinical and biochemical features between two groups were compared.Results(1) Of the 60 patients with Cushing's disease,23.3%(14/60)of patients(group A)did not yield results of suppression with the HDDST,and the others(group B)did.No difference was found in the age[(33.8?10.4 vs 36.2?11.2)years]and duration of illness[(2.1?1.6 vs 3.9?3.1)years]between two groups.(2)In clinical features,the patients in group A were more likely to have edema of lower limbs(64.3% vs 32.6%),hypokalemia (71.4% vs 28.3%),secondary diabetes(57.1% vs 26.1%)and purple striae(85.7% vs 54.3%,all P