title: Adrenocortical carcinoma masquerading as Cushing's disease.
abstract: Cushing's syndrome (CS) can be classified as adrenocorticotropic hormone (ACTH)-dependent or ACTH-independent depending on the ACTH levels. However, 30% of the patients with CS have ACTH levels in the 'grey zone' (5-20 pg/mL), thereby posing a challenge in establishing the aetiological diagnosis. In a patient with full-blown features of Cushing's syndrome with equivocal ACTH levels, and a pituitary microadenoma on contrast-enhanced MRI sella, can falsely lead to a diagnosis of Cushing's disease. Pituitary microadenoma, if <6 mm in size, may be an incidental finding (incidentaloma) in this scenario and can be present in ∼3-27% of the healthy population. Therefore, in a patient with CS with equivocal ACTH levels and a pituitary microadenoma, multiple samplings for ACTH and adrenal imaging should be performed to exclude ACTH-independent CS and if required, bilateral inferior petrosal sinus sampling to determine the source of ACTH excess.
authors.affiliation: Department of Endocrinology, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Kush Dev
authors.initials: KD
authors.lastname: Jarial
authors.affiliation: Department of Endocrinology, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Rama
authors.initials: R
authors.lastname: Walia
authors.affiliation: Department of Urology, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Santosh
authors.initials: S
authors.lastname: Kumar
authors.affiliation: Department of Endocrinology, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Anil
authors.initials: A
authors.lastname: Bhansali
mesh_terms: D000306:Adrenal Cortex Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism; D018268:Adrenocortical Carcinoma / Q000000981:diagnostic imaging* / Q000378:metabolism; D000324:Adrenocorticotropic Hormone / Q000032:analysis; D000328:Adult; D003937:Diagnosis, Differential; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D047748:Pituitary ACTH Hypersecretion / Q000378:metabolism*
chemical_list: D000324:Adrenocorticotropic Hormone