At an early stage, corticotroph microadenomas may sometimes remain undetected in patients with Cushing syndrome, even after examination with the most advanced diagnostic techniques, such as magnetic resonance imaging (MRI) and simultaneous bilateral petrosal sinus sampling. Therefore, occult eutopic corticotropin secretion may be misinterpreted as ectopic corticotropin production.
Recently, the peptide desmopressin (a vasopressin analog acting at hypothalamic-pituitary level) has been found to induce corticotropin hyperresponsiveness through specific receptor pathways in patients with the pituitary-dependent form of Cushing disease.1,2 We now report on a patient with developing pituitary corticotropin-dependent Cushing syndrome in whom MRI and bilateral catheterization of the inferior petrosal sinuses were unable to identify the pituitary autonomous corticotropin-secreting microadenoma. Therefore, the patient was tested with desmopressin to establish whether this test represents a precocious and sensitive method to identify a pituitary source of autonomous corticotropin secretion.
Chiodera P, Volpi R, Bianconcini M, Bortesi ML, Manfredi G, Coiro V. Desmopressin Test in Occult Eutopic Corticotropin Microadenoma. Arch Intern Med. 2002;162(7):840-841. doi:10.1001/archinte.162.7.840