far that analysed the incidence of hypopituitarism in patients with RCC and PESS differ in terms of study populations and testing methods for hormonal insufficiency.The insulin tolerance test (ITT) is the gold standard in the diagnosis of secondary adrenal insufficiency. However, it poses a risk for patients. In clinical practice, this test is often replaced with the tetracosactide stimulation test (Synacthen, cosyntropin). The classic version of the test uses the 250 μg Synacthen dose. However, some centres use a 1 μg dose because there is evidence for higher test sensitivity. Due to different laboratory methods used to determine cortisol levels, the cut-off value for the test is still disputable.In this study, we prospectively analysed a group of consecutive patients hospitalized at the