Endocrine Abstracts

Objective: Cushing’s disease (CD) is the most common cause of hypercortisolism after iatrogenic origin, it represents approximately 70% of patients with endogenous Cushing’s syndrome (CS) and ectopic ACTH secretion (10%). CD is caused by a corticotropin-secreting pituitary neuroendocrine tumor (ACTH-secreting Pit-NETs), 95% of cases as a microadenoma. In ACTH-dependent CS, differential diagnosis between CD and ectopic CS must be established. 40% of CD cases, any tumor is observed in the contrast-enhanced pituitary magnetic resonance imaging (MRI), and among the detected lesions, 85-87% are microadenomas Objective: to evaluate the usefulness of inferior petrosal sinus catheterization in the diagnosis of Cushing’s disease, the intrahypophyseal location of the ACTH-secreting Pit-NETs.

Patients and methods: A retrospective observational study was performed in all patients with CS that underwent bilateral inferior petrosal sinus catheterization (BIPSS) in a single center. Statistical analysis: Chi square test with Yate’s correction s and Cohen’s coefficient k were used as a measure of agreement between the exploratory techniques. Sensitivity, specificity, positive and negative predictive value, and positive and negative probability coefficient were also calculated. Chi-squared test was used to compare categorical data. Statistical analyses were performed using SPSS^® statistical software version 20.

Results: BIPSS was performed in 33 patients, 75.8% women, age 41.79 ± 14.60 years. BIPSS achieved a sensitivity of 96.67 %, IC 95% (0.80 − 0.99) and a specificity 100%, IC 95% (0.31− 0.96). Positive predictive value was 100%, IC 95% (0.85 − 0.99) and the negative predictive value was 75%, IC 95% (0.21 − 0.98). The global value or efficiency of the procedure 96.97% IC 95% (0.82 − 0.99). An intersinus gradient ≥ 1.4 was observed in 25 patients. In those who underwent surgery, tumor localization during surgery coincided with BIPSS results in 80% of cases; Kappa index was 0.658 (P 0.000), so there is good agreement between the lateralization result of the BIPSS and the location by surgery for the location of the ACTH-producing adenoma. No complications were recorded after BIPSS.

Conclusions: BIPSS plays a key role in the diagnosis of CD, and its results in the location of the tumor must be taken into account, since it shows good precision when compared with the surgical location of the tumor.