The 10 Hounsfield units unenhanced computed tomography attenuation threshold does not apply to cortisol secreting adrenocortical adenomas

Eur J Endocrinol. 2015 Sep;173(3):325-32. doi: 10.1530/EJE-15-0036.

Abstract

Context: Computed tomography (CT) unenhanced attenuation value of <10 Hounsfield units (HU) has an excellent specificity (98%) to diagnose lipid-rich adrenocortical adenomas (ACAs) with a weaker sensitivity (71%).

Objective: To determine from a routine clinical perspective if unenhanced attenuation value is influenced by cortisol secretion in ACAs.

Design: This was a retrospective study of cases collected between 2009 and 2012.

Setting: This study was conducted in a tertiary-care university hospital.

Patients: Seventy-two patients operated on for an ACA (Weiss score ≤ 2) were analysed. Thirty-four patients had an ACA oversecreting cortisol (Cush-ACA). Thirty-eight patients had an ACA without cortisol oversecretion (Non Hyper-ACA).

Main outcome measure: CT unenhanced attenuation value was correlated with the functional status. The Weiss score items were analysed.

Results: Among the 34 patients with a Cush-ACA a minority (n = 7) had an unenhanced attenuation value under 10 HU. Among the high precontrast density (> 10 HU) Cush-ACAs, washout analysis after contrast administration was consistent with the benign nature of the tumor in ∼ 60% of the cases. Less than 25% clear cells (lipid-rich cells), a Weiss score item, was present in 50% of the Cush-ACAs in favour of a lipid-poor content.

Conclusions: Unenhanced attenuation value has a poor sensitivity to diagnose an ACA in case of cortisol oversecretion due to poor lipid content. Nevertheless, the accuracy of washout analysis was preserved in the group of Cush-ACAs.

MeSH terms

  • Adrenal Cortex Neoplasms / diagnosis
  • Adrenal Cortex Neoplasms / diagnostic imaging*
  • Adrenal Cortex Neoplasms / metabolism
  • Adrenocortical Adenoma / diagnosis
  • Adrenocortical Adenoma / diagnostic imaging*
  • Adrenocortical Adenoma / metabolism
  • Adult
  • Aged
  • Cohort Studies
  • Female
  • Humans
  • Hydrocortisone / metabolism*
  • Male
  • Middle Aged
  • Retrospective Studies
  • Sensitivity and Specificity
  • Tomography, X-Ray Computed / methods

Substances

  • Hydrocortisone