Ectopic ACTH syndrome caused by bronchial carcinoid tumor indistinguishable from Cushing's disease

Differential gene expression profiles of POMC-related enzymes, transcription factors and receptors between non-pituitary and pituitary ACTH-secreting tumors

“…On the other hand, desmopressin stimulation test had a 40% false-positive response in EAS patients [24]. In fact, false-positive results were observed in 1 of 4 cases after CRH stimulation as recently reported [25] as well as in 2 of 3 cases after desmopressin stimulation in this study. The present study showed that CRHR1 mRNA expression in EAS was lower than CD as expected, and that V1bR mRNA expression was comparable between EAS and CD.…”

Clinical features and management of ectopic ACTH syndrome at a single institute in Japan

“…Diagnostic imaging test by SRS not available in Japan yet was approved by the Ethics Committee of TMDU Hospital; written informed consent was obtained from each patient. Some cases have been reported elsewhere [5][6][7][8][9][10].…”

“…Among 10 cases who underwent IPS/CS sampling, 8 (80%) showed no ACTH gradient before and after CRH stimulation except for two; Case 4 (olfactory neuroblastoma) with C/P ratio (2.8) under the basal state [5] and Case 8 (pulmonary carcinoid tumor) with C/P ratio (3.5) after CRH stimulation [9].…”

The role of inferior petrosal sinus sampling in ACTH-dependent Cushing's syndrome: review and joint opinion statement by members of the Italian Society for Endocrinology, Italian Society for Neurosurgery, and Italian Society for Neuroradiology

“…A scattering of cases have been reported in major case series (Table 1) as well as in individual case reports. 9,30,42,58,62,69 Overall, although the paucity of reported cases allows only an approximate calculation, the specificity of IPSS may be estimated at 90%-95%. In a number of these cases, patients were subjected to transsphenoidal surgery, but the postoperative course suggested an ectopic source, and the causative lesion-in some cases already evident prior to pituitary surgery but deemed incidental at the time-was subsequently removed.…”

“…58,62,69 Lastly, IPSS has been used in patients with ACTHdependent Cushing's syndrome who did not present a clear pituitary lesion, even though testing was indicative of a pituitary lesion. This approach is burdened by the low prevalence of visible pituitary tumors in patients with Cushing's disease; indeed, even the most sensitive pituitary imaging techniques proved negative in 20%-50% of patients in whom an ACTH-secreting adenoma was confirmed by surgery.…”