Clinical Utility of Noncontrast Computed Tomography Attenuation Value (Hounsfield Units) to Differentiate Adrenal Adenomas/Hyperplasias from Nonadenomas: Cleveland Clinic Experience

• Published in: The journal of clinical endocrinology and metabolism Vol. 90; no. 2; pp. 871 - 877
• Main Authors: Hamrahian, Amir H, Ioachimescu, Adriana G, Remer, Erick M, Motta-Ramirez, Gaspar, Bogabathina, Hari, Levin, Howard S, Reddy, Sethu, Gill, Inderbir S, Siperstein, Allan, Bravo, Emmanuel L
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Endocrine Society 01.02.2005; Copyright by The Endocrine Society
• Subjects: Adenoma - diagnostic imaging; Adolescent; Adrenal Gland Neoplasms - diagnostic imaging; Adrenals. Adrenal axis. Renin-angiotensin system (diseases); Adrenocortical Hyperfunction - diagnostic imaging; Adult; Biological and medical sciences; Diagnosis, Differential; Endocrinopathies; Female; Fundamental and applied biological sciences. Psychology; Humans; Male; Medical sciences; Middle Aged; Non tumoral diseases. Target tissue resistance. Benign neoplasms; Retrospective Studies; Tomography, X-Ray Computed; Vertebrates: endocrinology; Endocrinopathy; Adrenal cortex diseases; Radiodiagnosis; Hyperadrenocorticism; Adenoma; Enzymopathy; Congenital adrenal hyperplasia syndrome; Adrenal gland diseases; Medical imagery; Attenuation; Computerized axial tomography; Benign neoplasm; Endocrinology
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/jc.2004-1627

Radiological characterization of an adrenal tumor as adenoma may decrease the need for follow-up imaging studies, biopsies, and unnecessary adrenalectomies. We retrospectively reviewed 299 adrenalectomies in 290 patients at Cleveland Clinic Foundation over a recent 5-yr period to assess the value of noncontrast Hounsfield units (HU) in characterizing whether an adrenal mass is adenoma or nonadenoma. The mean (± sd) HU value for the adrenocortical adenoma/hyperplasia group was 16.2 ± 13.6 and significantly lower (P < 0.0001) than primary adrenocortical cancers (36.9 ± 4.1), metastases (39.2 ± 15.2), and pheochromocytomas (38.6 ± 8.2). The sensitivity and specificity for 10- and 20-HU cutoff values to differentiate adenomas/hyperplasias from nonadenomas were 40.5 and 100% and 58.2 and 96.9%, respectively. The size of the adrenal tumor had less value with only 40.7 and 81.3% sensitivity and 94.7 and 61.4% specificity for 2- and 4-cm cutoff values. A combination of less than or equal to 4-cm adrenal mass size and noncontrast computed tomography HU less than or equal to 20 had 42.1% sensitivity and 100% specificity. Our study, the largest with surgical histopathology as the gold standard for diagnosis, supports a noncontrast computed tomography attenuation value of 10 HU as a safe cutoff value to differentiate adrenal adenomas/hyperplasias from nonadenomas.