Diagnostic Dilemma in Interpreting Inferior Petrosal Sinus Sampling in Suspected Cyclical Cushing’s Disease in an Adolescent
https://doi.org/10.15605/jafes.041.S1
- Author:
Nicholas Wee Wern Phan
1
;
Pei Sun Tan
1
;
Subashini Rajoo
1
;
Vanusha A/P Devaraja Pillai
2
;
Shazatul Reza binti Mohd Redzuan
1
;
Gayathri Devi Krishnan
1
;
Sharifah Noor Adrilla Long Mohd Noor Affendi
1
Author Information
1. Endocrine Unit, Department of Internal Medicine, Hospital Kuala Lumpur
2. Department of Internal Medicine, Hospital Melaka
- Publication Type:Journal Article
- MeSH:
Adolescent;
Humans;
Petrosal Sinus Sampling
- From:
Journal of the ASEAN Federation of Endocrine Societies
2026;41(S1):90-
- CountryPhilippines
- Language:English
-
Abstract:
Introduction:Cushing’s disease in adolescents is rare and frequently
difficult to diagnose due to overlapping features with
common pubertal and metabolic conditions. We present
an adolescent who underwent inferior petrosal sinus
sampling (IPSS) with possible cyclical Cushing’s disease,
highlighting the diagnostic challenges and the interpretive
value of IPSS.
Case:A 16-year-old female presented with progressive weight
gain, acne, hirsutism, secondary amenorrhea, proximal
myopathy, violaceous striae, and facial plethora over 1 year.
Her 24-hour urinary cortisol was >3,310 nmol/L with failure
of suppression following a 1-mg overnight dexamethasone
suppression test (701 nmol/L). Her adrenocorticotropic
hormone (ACTH) was raised (77.9 pg/mL), consistent with
ACTH-dependent Cushing syndrome. Her hemoglobin
A1c was 5.9%, and she has low bone mass for age with a
Z score of -2.9 at the Lumbar spine.
Pituitary magnetic resonance imaging identified a rightsided microadenoma measuring 0.6 × 0.5 cm, while
computed tomography of the thorax, abdomen, and
pelvis showed no ectopic source. IPSS with desmopressin
stimulation was performed to confirm the ACTH source.
No steroidogenesis inhibitors were administered prior to
testing. Notably, cortisol levels during IPSS were relatively
low, with midnight cortisol of 91 nmol/L and morning
cortisol of 200 nmol/L, suggesting testing during a trough
phase of possible cyclical hypercortisolism. Despite this,
IPSS demonstrated a significant central-to-peripheral
ACTH gradient supporting a pituitary source.
Conclusion:This case highlights the diagnostic dilemma of interpreting
IPSS in suspected cyclical Cushing’s disease. Fluctuating
cortisol secretion may result in discordant biochemical
findings and complicate localization studies. IPSS findings should be interpreted cautiously and integrated with
clinical features, imaging, and serial biochemical monitoring. Recognition of cyclical disease patterns is essential to
ensure appropriate management in adolescent patients.
- Full text:2026080414500932392EP_A127.pdf
