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Dual bronchial carcinoids and Cushing's syndrome with a paradoxical response to dexamethasone and a false positive outcome of inferior petrosal sinus sampling.

Burman, Pia; Lethagen, ÅsaLinda LU ; Ivancev, Krasnodar; Johansson, Leif LU and Sundin, Anders (2008) In European Journal of Endocrinology 159. p.483-488
Abstract
Objective Establishing the cause of Cushing's syndrome can be a considerable challenge, in particular in ectopic ACTH syndrome, and often requires a combination of biochemical tests and imaging procedures. Subject A 27-year-old man presented with signs of Cushing's syndrome. P-ACTH levels were 3 times above the ULN and free urinary cortisol in the order of 1900 nmol/24 h. The work-up showed remarkable results. Results A 2-day low-dose dexamethasone suppression test demonstrated paradoxical increases in cortisol. Sampling from the inferior petrosal sinuses (BIPSS) showed a central to peripheral ACTH ratio of 4.7 after CRH stimulation, i.e. indicated pituitary disease, but MRI of the pituitary was normal and baseline P-CRH <1.0 (ref.... (More)
Objective Establishing the cause of Cushing's syndrome can be a considerable challenge, in particular in ectopic ACTH syndrome, and often requires a combination of biochemical tests and imaging procedures. Subject A 27-year-old man presented with signs of Cushing's syndrome. P-ACTH levels were 3 times above the ULN and free urinary cortisol in the order of 1900 nmol/24 h. The work-up showed remarkable results. Results A 2-day low-dose dexamethasone suppression test demonstrated paradoxical increases in cortisol. Sampling from the inferior petrosal sinuses (BIPSS) showed a central to peripheral ACTH ratio of 4.7 after CRH stimulation, i.e. indicated pituitary disease, but MRI of the pituitary was normal and baseline P-CRH <1.0 (ref. <5) pmol/L. CT scan of the lungs showed 2 oval-shaped masses, 1.3 x 1.8 and 1.3 x 2 cm, in the middle lobe. Both were positive at somatostatin receptor scintigraphy, compatible with tumors or inflammatory lesions. Subsequently, 11C-5-hydroxytryptophan-PET showed distinct uptake in the tumors but not elsewhere. Two carcinoids situated 3 cm apart, both staining for ACTH, were removed at surgery. Conclusion This unusual case with dual bronchial carcinoids inducing hypercortisolism illustrates the problems with identifying the source of ACTH in Cushing s syndrome. Possibly, the false positive result at BIPSS reflects an unusual sensitivity of the pituitary corticotrophs to CRH in this patient since ectopic CRH secretion and/or eucortisolism at the time of the procedure could be ruled out. The work-up illustrates the great value of 11C-5-hydroxytryptophan-PET as a diagnostic procedure when other investigations have produced ambiguous results. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
European Journal of Endocrinology
volume
159
pages
483 - 488
publisher
Society of the European Journal of Endocrinology
external identifiers
  • wos:000260169900018
  • pmid:18625689
  • scopus:54049084525
ISSN
1479-683X
DOI
10.1530/EJE-08-0385
language
English
LU publication?
yes
id
a80f55d1-0cdb-4a58-8f4d-0e7eade95140 (old id 1181157)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/18625689?dopt=Abstract
date added to LUP
2008-08-08 15:49:35
date last changed
2017-01-01 07:41:16
@article{a80f55d1-0cdb-4a58-8f4d-0e7eade95140,
  abstract     = {Objective Establishing the cause of Cushing's syndrome can be a considerable challenge, in particular in ectopic ACTH syndrome, and often requires a combination of biochemical tests and imaging procedures. Subject A 27-year-old man presented with signs of Cushing's syndrome. P-ACTH levels were 3 times above the ULN and free urinary cortisol in the order of 1900 nmol/24 h. The work-up showed remarkable results. Results A 2-day low-dose dexamethasone suppression test demonstrated paradoxical increases in cortisol. Sampling from the inferior petrosal sinuses (BIPSS) showed a central to peripheral ACTH ratio of 4.7 after CRH stimulation, i.e. indicated pituitary disease, but MRI of the pituitary was normal and baseline P-CRH &lt;1.0 (ref. &lt;5) pmol/L. CT scan of the lungs showed 2 oval-shaped masses, 1.3 x 1.8 and 1.3 x 2 cm, in the middle lobe. Both were positive at somatostatin receptor scintigraphy, compatible with tumors or inflammatory lesions. Subsequently, 11C-5-hydroxytryptophan-PET showed distinct uptake in the tumors but not elsewhere. Two carcinoids situated 3 cm apart, both staining for ACTH, were removed at surgery. Conclusion This unusual case with dual bronchial carcinoids inducing hypercortisolism illustrates the problems with identifying the source of ACTH in Cushing s syndrome. Possibly, the false positive result at BIPSS reflects an unusual sensitivity of the pituitary corticotrophs to CRH in this patient since ectopic CRH secretion and/or eucortisolism at the time of the procedure could be ruled out. The work-up illustrates the great value of 11C-5-hydroxytryptophan-PET as a diagnostic procedure when other investigations have produced ambiguous results.},
  author       = {Burman, Pia and Lethagen, ÅsaLinda and Ivancev, Krasnodar and Johansson, Leif and Sundin, Anders},
  issn         = {1479-683X},
  language     = {eng},
  pages        = {483--488},
  publisher    = {Society of the European Journal of Endocrinology},
  series       = {European Journal of Endocrinology},
  title        = {Dual bronchial carcinoids and Cushing's syndrome with a paradoxical response to dexamethasone and a false positive outcome of inferior petrosal sinus sampling.},
  url          = {http://dx.doi.org/10.1530/EJE-08-0385},
  volume       = {159},
  year         = {2008},
}