TY - JOUR
T1 - Cost-effectiveness and accuracy of the tests used in the differential diagnosis of Cushing's syndrome
AU - Puig, J.
AU - Wägner, A.
AU - Caballero, A.
AU - Rodríguez-Espinosa, J.
AU - Webb, S.M.
PY - 1999/6/1
Y1 - 1999/6/1
N2 - Aim: Establish the minimal biochemical and radiological examinations necessary and their cost-effectiveness to accurately diagnose the etiology of Cushing's syndrome (CS). Material and Methods: In 71 patients with CS followed between 1982 and 1997 biochemical studies (basal ACTH, 8mg dexamethasone suppression test -HDST-, metyrapone stimulation test -MST-, or inferior petrosal sinus catheterization -IPSC-) and radiological investigations (abdominal CT scan, pituitary CT scan or MRI) were performed. Once pathology confirmed the diagnosis (48 pituitary Cushing's disease-CD, 17 adrenal neoplasms, 2 bilateral macronodular hyperplasia -BMH-, and 4 ectopic ACTH syndrome -ES-), the sensitivity, specificity, positive and negative predictive value of the different studies was calculated to establish the most accurate and cost-effective diagnostic protocol. Results: In ACTH-independent CS (ACTH ≤ 9 pg/ml; normal 9 to 54) a unilateral tumor was identified on abdominal CT scanning in 17, and BMH in 1; the other BMH had detectable ACTH (43.2 pg/ml). In ACTH-dependent CS, ACTH was > 9 pg/ml and IPSC (performed in 22) correctly identified 20 patients with CD and differentiated them from 2 with an ES (100 % specificity and sensitivity). Pituitary MRI or CT did not disclose an adenoma in 41.7% of patients with CD, and was reported to exhibit a microadenoma in 2 of the 4 patients with ES. HDST and MST were of no additional use in the differentiation between CD and ES. Conclusions: Once CS is diagnosed low ACTH and an abdominal CT scan correctly identified all patients of adrenal origin. In ACTH-dependent CS IPSC was the best predictive test to differentiate CD from ES. BMH may behave as ACTH-dependent or independent. The other biochemical and radiological studies performed are not cost-effective and may even be misleading, and should not be routinely performed.
AB - Aim: Establish the minimal biochemical and radiological examinations necessary and their cost-effectiveness to accurately diagnose the etiology of Cushing's syndrome (CS). Material and Methods: In 71 patients with CS followed between 1982 and 1997 biochemical studies (basal ACTH, 8mg dexamethasone suppression test -HDST-, metyrapone stimulation test -MST-, or inferior petrosal sinus catheterization -IPSC-) and radiological investigations (abdominal CT scan, pituitary CT scan or MRI) were performed. Once pathology confirmed the diagnosis (48 pituitary Cushing's disease-CD, 17 adrenal neoplasms, 2 bilateral macronodular hyperplasia -BMH-, and 4 ectopic ACTH syndrome -ES-), the sensitivity, specificity, positive and negative predictive value of the different studies was calculated to establish the most accurate and cost-effective diagnostic protocol. Results: In ACTH-independent CS (ACTH ≤ 9 pg/ml; normal 9 to 54) a unilateral tumor was identified on abdominal CT scanning in 17, and BMH in 1; the other BMH had detectable ACTH (43.2 pg/ml). In ACTH-dependent CS, ACTH was > 9 pg/ml and IPSC (performed in 22) correctly identified 20 patients with CD and differentiated them from 2 with an ES (100 % specificity and sensitivity). Pituitary MRI or CT did not disclose an adenoma in 41.7% of patients with CD, and was reported to exhibit a microadenoma in 2 of the 4 patients with ES. HDST and MST were of no additional use in the differentiation between CD and ES. Conclusions: Once CS is diagnosed low ACTH and an abdominal CT scan correctly identified all patients of adrenal origin. In ACTH-dependent CS IPSC was the best predictive test to differentiate CD from ES. BMH may behave as ACTH-dependent or independent. The other biochemical and radiological studies performed are not cost-effective and may even be misleading, and should not be routinely performed.
KW - Cost-effective
KW - Cushing's syndrome
KW - Diagnosis
U2 - 10.1023/A:1009936622150
DO - 10.1023/A:1009936622150
M3 - Article
SN - 1386-341X
VL - 1
SP - 125
EP - 132
JO - Pituitary
JF - Pituitary
IS - 2
ER -