Corticotropinoma As The Underlying Cause Of Intermittent Cushing'S Syndrome In A Patient Previously Diagnosed With Primary Pigmented Nodular Adrenocortical Disease

We are presenting the difficulties we encountered with the female patient with previously diagnosed primary pigmented nodular adrenal disease (PPNAD) and conflicting hormonal and radiological findings a few years later. The patient underwent unilateral adrenalectomy in 2010. Despite repeated search, no other components of Carney's complex have ever been discovered. 8 years later, she was diagnosed with ACTH-dependant Cushing's syndrome. Pituitary MRI showed a lesion of less than 3 mm on the left side of adenohypophysis (suggesting microadenoma) and bilateral inferior petrosal sinus sampling (BIPSS) confirmed this suspicion. The patient underwent effective transsphenoidal adenomectomy and is now eucortisolaemic. The genetic testing for PRKAR1A mutations was negative and the second histopathological evaluation raised some considerable doubts whether the diagnosis of PPNAD was stated correctly.