Endocrine Abstracts

Objective: Cushing’s disease (CD) accounts for approximately 80% of cases of Cushing’s syndrome. Diagnosis of CD is difficult, it is carried out with a screening test and confirmation test. The aim of this study is to describe the diagnostic results of the different diagnostic tests used in the diagnosis of CD in our environment.

Patients and methods: Retrospective descriptive study of patients with CD. We included all patients diagnosed with CD (2005–2017) treated with transsphenoidal surgery, and whose tumor sample was analyzed in the Department of Cell Biology, Physiology and Immunology of the University From Córdoba. Variables analyzed: age, sex, basal cortisol level, 24-hour urinary cortisol level, midnight plasma cortisol level, midnight salivary cortisol level, low-dose dexamethasone (DST), ACTH level, high-dose DST, MRI pituitary and cavernous sinus sampling with desmopressin stimulation.

Results: Thirty-seven patients with CD. Age 45.03±13.13 years. Women: 94.6%. Biochemical determinations at diagnosis are shown in the table. Patients presented pathological determination: 100% cortisol after 1 mg DST, 77.1% 24-hour urinary cortisol level, 100% nocturnal plasma cortisol, and 100% nocturnal salivary cortisol. Cortisol after DXT 2 mg was pathological in 95.8% and cortisol after DXT 8 mg in 95% of the cases. In all patients, MRI pituitary with contrast was performed, detecting 48.6% macroadenomas (n: 18), 43.2% microadenomas (n: 16) and 8.1% (n: 3) without findings. Size adenoma: 11.66±8.57 mm (me ± RIC: 8±11 mm). Cavernous sinus sampling with desmopressin stimulation was performed in 13 patients (35.1%), indicated when no lesion was detected in the pituitary test or it was less than 6 mm, in all of them ACTH gradient confirmed the diagnosis of CD.

Conclusions: Cortisol after 1 mg DST, nocturnal plasma cortisol and nocturnal salivary cortisol were pathological in all patients. MRI pituitary detected most ACTH-producing adenomas, almost half of the macroadenomas. Cavernous sinus sampling with desmopressin stimulation confirmed the diagnosis in all patients not diagnosed with MRI pituitary.