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

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 (nZ7) had an unenhanced attenuation value under 10 HU. Among the high precontrast density (O10 HU) Cush-ACAs, washout analysis after contrast administration was consistent with the benign nature of the tumor in w60% 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.

Chemical shift magnetic resonance imaging could predict subclinical cortisol production from an incidentally discovered adrenal mass

“…Our results are in line with two previous CT studies in patients with CS demonstrating an inverse linear relationship between precontrast CT attenuation level and the percentage of lipid‐rich cells . Taken together, our data support the concept that cortisol hypersecretion by an adrenal adenoma may be associated with distinctive radiological characteristics.…”

“…The utilization of imaging parameters for the prediction of the functionality and particularly the cortisol excess has been investigated in very few studies. Chambre and colleagues reported that the unenhanced attenuation value of CT had very poor sensitivity to diagnose adrenal cortical adenomas (ACA) in patients with CS . The study by Mosconi and colleagues showed that an adrenal protocol CT scan could predict autonomous cortisol secretion from an AI …”

“…Chambre and colleagues reported that the unenhanced attenuation value of CT had very poor sensitivity to diagnose adrenal cortical adenomas (ACA) in patients with CS. 11 The study by Mosconi and colleagues showed that an adrenal protocol CT scan could predict autonomous cortisol secretion from an AI. 12 At present, to our knowledge, there are no studies on the relationship between MRI parameters of the adrenal tumours associated with cortisol excess and their pathologic, clinical and hormonal characteristics.…”

Adrenalectomy for incidentaloma: lessons learned from a single‐centre series of 274 patients

“…These changes have allowed surgical treatment for most atypical benign tumours to be ruled out, that is, poor lipid nonfunctioning adenomas with atypical features on CT scan. These non‐secreting undetermined adrenal masses with spontaneous densities higher than 10 Hounsfield unit (HU), as indicated by CT scan, have been extensively studied . There are several benign imaging findings that rule out the presence of malignancy with excellent negative predictive value.…”

“…There are several benign imaging findings that rule out the presence of malignancy with excellent negative predictive value. These include the following: (i) spontaneous density less than 10 HU on unenhanced CT scan followed with relative or absolute washout measurement greater than 40% or 60% on contrast‐enhanced CT scan; (ii) chemical shift MRI with a decrease of signal intensity greater than 20% between in‐ and opposed‐phase images; and (iii) an adrenal‐to‐liver standard uptake value less than 1.45 on 18 F‐fluorodeoxyglucose PET . Surgery is still required in patients with indeterminate adrenal masses, especially when patients have a long projected life expectancy, because of the risks of tumour growth and hormonal oversecretion development.…”