Cushing syndrome: pituitary CT scanning.

Area of Science:

• Endocrinology
• Neurosurgery
• Radiology

Background:

• Cushing syndrome requires accurate diagnosis of the underlying cause, whether pituitary adenoma, adrenal adenoma, or ectopic adrenocorticotropic hormone (ACTH)-producing tumor.
• Distinguishing between these sources is crucial for effective patient treatment and management.

Purpose of the Study:

• To evaluate the utility of computed tomography (CT) of the pituitary gland in diagnosing or excluding ACTH-producing pituitary adenomas.
• To assess CT's ability to predict the adenoma's location within the pituitary gland in patients with Cushing syndrome.

Main Methods:

• Prospective evaluation of 57 patients diagnosed with Cushing syndrome.
• Analysis of computed tomography (CT) scan findings of the pituitary gland in relation to surgically confirmed diagnoses.

Main Results:

• CT scans were normal in 35 of 50 patients with Cushing disease and 7 with ectopic ACTH-producing tumors.
• Abnormal CT findings were observed in 15 patients with Cushing disease, including 8 macroadenomas and 7 microadenomas.
• CT demonstrated low sensitivity (30%) and diagnostic accuracy (39%) for detecting ACTH-producing pituitary tumors.

Conclusions:

• Computed tomography (CT) of the pituitary gland has limited value in diagnosing ACTH-producing pituitary tumors in Cushing syndrome.
• Alternative diagnostic modalities are necessary to confirm the pituitary origin of excessive ACTH secretion in the majority of patients.