ACTH-dependent Cushing’s Syndrome: Diagnostic Pitfalls in Concomitant Non-secreting Pituitary Adenomas

OBJECTIVES: To describe the possible pitfalls in correctly interpreting clinical, radiological and biochemical findings in ACTH-dependent Cushing’s syndrome. METHODS: We describe a case of a pituitary adenoma visualized at MRI not correlated with an ACTH-dependent Cushing’s syndrome. RESULTS: Radiological imaging and hormonal testing can be misleading in suspected pituitary ACTH-related Cushing’s syndrome. CONCLUSION: Correct interpretation of the initial clinical presentation can help in the proper diagnosis and treatment of ACTH-dependent Cushing’s syndrome. LEARNING POINTS: Occult neoplasia should always be excluded in cases of severe ACTH-dependent Cushing’s syndrome. A positive MRI result can be misleading. Ectopic ACTH-dependent syndrome is generally associated with a peculiar phenotype.