In our patient the pituitary MRI showed both left and right lesions of 9 mm and 6 mm, respectively: although the radiological finding of the left lesion was suggestive of an ACTH-secreting adenoma, we still preferred to perform bilateral inferior petrosal sinus sampling (BIPSS) [18]: according to the methodology described in the literature, we measured ACTH at baseline and at 3, 5, and 10 minutes after CRH administration. The gene discussed is POMC; the disease is adenoma.