Cushing Disease Diagnosed with Bilateral Simultaneous Inferior Petrosal Sinus Sampling

ABSTRACT

The most common endogenous cause of Cushing's syndrome is Cushing's disease. The evaluation of patients with suspected Cushing's disease and syndrome requires an understanding of the proper use and limitations of the tests commonly included in the diagnostic work-up. The best screening test for Cushing's syndrome is a 24-hour urine collection with analysis for urinary free cortisol excretion. Low-dose and high-dose dexamethasone suppression tests, corticotropin assays, a corticotropin-release hormone stimulation test and inferior petrosal sinus cathaterization may be required for a definitive diagnosis. MRI is useful in localizing the lesion but some limitations. Surgical removal of the lesion by a trans-sphenoidal appraoch is usually successful, but long-term follow-up is required. We report a case of Cushing disease which shows such typical clinical characteristics of Cushing syndrome as weight gain, skin lesions, truncal obesity, striae, hypertension.