Correlation Between Size and Function of Unilateral and Bilateral Adrenocortical Nodules: An Observational Study

Association between contralateral adrenal and hypothalamus-pituitary-adrenal axis in benign adrenocortical tumors

Context

Adrenal incidentaloma (AI) is commonly discovered on cross-sectional imaging. Mild autonomous cortisol secretion is the most common functional disorder detected in AI.

Objective

To delineate the association between radiological characteristics of benign adrenocortical tumors and hypothalamus-pituitary-adrenal (HPA) axis.

Methods

In the study, 494 patients diagnosed with benign unilateral adrenocortical tumors were included. Mild autonomous cortisol secretion (MACS) was diagnosed when cortisol after 1mg-dexamethasone suppression test (1-mg DST) was in the range of 1.8-5ug/dl. Non-functional adrenocortical tumor (NFAT) was diagnosed as cortisol following 1-mg DST less than 1.8ug/dL. We performed Logistics regression and causal mediation analyses, looking for associations between radiological characteristics and the HPA axis.

Results

Of 494 patients, 352 (71.3%) with NFAT and 142 (28.7%) with MACS were included. Patients with MACS had a higher tumor diameter, thinner contralateral adrenal gland, and lower plasma ACTH and serum DHEAS than those with NFAT. ACTH (OR 0.978, 0.962-0.993) and tumor diameter (OR 1.857, 95%CI, 1.357-2.540) were independent factors associated with decreased serum DHEAS (all P<0.05). ACTH was also associated with decreased contralateral adrenal diameter significantly (OR 0.973, 95%CI, 0.957-0.988, P=0.001). Causal mediation analysis showed ACTH mediated the effect significantly for the association between 1-mg DST results and DHEAS level (Pmediation<0.001, proportion=22.3%). Meanwhile, we found ACTH mediated 39.7% of the effects of 1-mg DST on contralateral adrenal diameter (Pmediation=0.012).

Conclusions

Patients with MACS had thinner contralateral adrenal glands and disturbed HPA axes compared with NFAT. ACTH may partially be involved in mediating the mild autonomous cortisol secretion to DHEAS and the contralateral adrenal gland.

CT of hemorrhagic adrenal adenomas: radiologic-pathologic correlation

PURPOSE

To describe the appearance of chronically hemorrhagic adenomas on adrenal protocol CT and correlate imaging with pathologic findings.

METHODS

Retrospective case series of adult patients with resected adrenal adenomas showing internal hemorrhage at histology. Seven of nine patients underwent pre-operative adrenal protocol CT and 2/7 underwent unenhanced CT with portal venous phase CT. Two abdominal radiologists in consensus assessed the CT images for the presence of calcifications, macroscopic fat, cystic/necrotic appearance, and the presence, pattern, and percent nodule volume of areas < 10 HU on unenhanced CT. Absolute washout was calculated using a large ROI, and ROIs on the highest and lowest attenuating regions on the portal venous phase.

RESULTS

Mean adenoma length was 4.9 cm. All adenomas had areas measuring < 10 HU on unenhanced CT, ranging from < 20 to > 80% nodule volume. Calcifications were present in 4/9 adenomas and gross fat in 4/9 on CT. Of the seven cases with adrenal protocol CT, the absolute washout was < 60% in 5/7 using the large ROI, 5/7 using the low attenuation ROI, and 7/7 using the high attenuation ROI. At histology, all nine cases had microscopic evidence of hemorrhage, lipid rich adenoma cells, and fibrosclerosis. Myelolipomatous changes were identified in 4/9 cases, with the remaining five cases showing lipomatous metaplasia without a myeloid component.

CONCLUSION

Chronically hemorrhagic adrenal adenomas demonstrated variable areas < 10 HU on unenhanced CT corresponding to lipid rich adenoma cells. Absolute washout was most often < 60%, hypothesized to be due to fibrosclerosis within the adenomas.

A machine learning approach to distinguishing between non-functioning and autonomous cortisol secreting adrenal incidentaloma on magnetic resonance imaging using texture analysis

PURPOSE

To investigate the possibility of distinguishing between nonfunctioning adrenal incidentalomas (NFAI) and autonomous cortisol secreting adrenal incidentalomas (ACSAI) with a model created with magnetic resonance imaging (MRI)-based radiomics and clinical features.

METHODS

In this study, 100 adrenal lesions were evaluated. The lesions were segmented on unenhanced T1-weighted in-phase (IP) and opposed-phase (OP) as well as on T2-weighted (T2-W) 3Tesla MRIs. The LASSO regression model was used to select potential predictors from 108 texture features for each sequence. Subsequently, a combined radiomics score and clinical features were created and compared.

RESULTS

A significant difference was found between median rad-scores for ACSAI and NFAI in training and test sets (p < 0.05 for all sequences). Multivariate logistic regression analysis revealed that the length of the tumor (OR = 1.09, p = 0.007) was an independent risk factor related to ACSAI. Multivariate logistic regression analysis was used for building clinical-radiomics (combined) models. The Op, IP, and IP plus T2-W model had a higher performance with area under curve (AUC) 0.758, 0.746, and 0.721 on the test dataset, respectively.

CONCLUSION

ACSAI can be distinguished from NFAI with high accuracy on unenhanced MRI. Radiomics analysis and the model constructed by machine learning algorithms seem superior to another radiologic assessment method. The inclusion of chemical shift MRI and the length of the tumor in the radiomics model could increase the power of the test.

The association between adrenal adenoma size, autonomous cortisol secretion and metabolic derangements

OBJECTIVE

Autonomous cortisol secretion (ACS) is common in patients with adrenal incidentalomas (AI). ACS is associated with increased cardiovascular morbidity and mortality. Data regarding the association between radiological characteristics of adrenal adenomas, their hormonal functionality and metabolic outcomes, are scarce and inconclusive. In this study, we aim to delineate the association between radiological characteristics of AI, ACS and metabolic status.

METHODS

A cross-sectional study of 77 patients with AI who underwent a comprehensive hormonal evaluation. Radiological assessments were performed by an independent radiologist blinded to the clinical and hormonal phenotype of each case. Linear regression models were used to evaluate the association between post dexamethasone suppression test (DST) cortisol levels, metabolic indices and radiological measurements.

RESULTS

Mean maximal adenoma diameter was greater in patients with versus without ACS (20.35 ± 6 vs. 27.09 ± 9.3 mm, respectively, p < .01). Maximal adenoma diameter was found to be positively and linearly correlated with post-DST morning cortisol levels across their entire range (R = .474, p < .01). Linear correlations between maximal adenoma diameter and indices of glycemic control showed a correlation coefficient (R) of .481 and .463 for fasting plasma glucose (FPG) and haemoglobin A1c (HbA1c), respectively, p < .01. When analysis included only patients with ACS, an R = .584 and R = .565 was observed for FPG and HbA1c, respectively (p < .01 for both). The association between maximal adenoma diameter and both FPG and post-DST morning cortisol intensified in patients with metabolic syndrome.

CONCLUSION

There is a quantitative positive mild correlation between AI size and both cortisol autonomy and metabolic parameters.

Maximum adenoma diameter, regardless of uni- or bilaterality, is a risk factor for autonomous cortisol secretion in adrenal incidentalomas

PURPOSE

To evaluate differences between patients with unilateral and bilateral adrenal incidentalomas (AIs) in the prevalence of autonomous cortisol secretion (ACS) and related comorbidities.

METHODS

In this multicentre retrospective study, AIs ≥ 1 cm without overt hormonal excess were included in the study. ACS was defined by a post-dexamethasone suppression test (DST) serum cortisol ≥ 5.0 µg/dl, in the absence of signs of hypercortisolism. For the association of ACS with the prevalence of comorbidities, post-DST serum cortisol was also analysed as a continuous variable.

RESULTS

Inclusion criteria were met by 823 patients, 66.3% had unilateral and 33.7% bilateral AIs. ACS was demonstrated in 5.7% of patients. No differences in the prevalence of ACS and related comorbidities were found between bilateral and unilateral AIs (P > 0.05). However, we found that tumour size was a good predictor of ACS (OR = 1.1 for each mm, P < 0.001), and the cut-off of 25 mm presented a good diagnostic accuracy to predict ACS (sensitivity of 69.4%, specificity of 74.1%). During a median follow-up time of 31.2 (IQR = 14.4-56.5) months, the risk of developing dyslipidaemia was increased in bilateral compared with unilateral AIs (HR = 1.8, 95% CI = 1.1-3.0 but, this association depended on the tumour size observed at the end of follow-up (HR adjusted by last visit-tumour size = 0.9, 95% CI = 0.1-16.2).

CONCLUSIONS

Tumour size, not bilaterality, is associated with a higher prevalence of ACS. During follow-up, neither tumour size nor bilaterality were associated with the development of new comorbidities, yet a larger tumour size after follow-up explained the association of bilateral AIs with the risk of dyslipidaemia.

Can abdominal CT features predict autonomous cortisol secretion in patients with adrenal nodules?

PURPOSE

To determine if CT features of adrenal nodules and of the remainder of the abdomen can predict autonomous cortisol secretion (ACH) in patients with adrenal nodules, and to identify a nodule size threshold below which ACH is unlikely.

METHODS

Retrospective review of adult patients with adrenal nodules who underwent CT of abdomen and 1-mg Dexamethasone suppression test within 1 year of each other. Patients were considered to have no ACH if serum cortisol was ≤ 1.8 µg/dL after the 1-mg dexamethasone suppression test and to have possible or definite autonomous cortisol secretion if serum cortisol was > 1.8 µg/dL. The following CT features were assessed: Adrenal nodule length, nodule width, unenhanced nodule attenuation, contralateral adrenal gland thickness, visceral and subcutaneous adipose tissue area, skeletal muscle area and density, and unenhanced liver attenuation.

RESULTS

29 patients had no autonomous cortisol secretion and 29 patients had possible or definite autonomous cortisol secretion. Nodule length and width were the only two variables that significantly differed between patients with nonfunctional nodules and those with possibly or definitely functional nodules. Using a threshold nodule length of 1.5 cm, the sensitivity and specificity for predicting possible or definite autonomous cortisol secretion was 93.1% and 37.9%, respectively.

CONCLUSION

Autonomous cortisol secretion in patients with adrenal nodules correlates with increasing nodule size. A nodule length threshold of 1.5 cm provides 93.1% sensitivity for predicting possible or definite ACH based on the 1-mg Dexamethasone suppression test.

Steroidogenesis in patients with adrenal incidentalomas: Extended steroid profile measured by liquid chromatography-mass spectrometry after ACTH stimulation and dexamethasone suppression

OBJECTIVE

Describe the secretion and profile of adrenal steroids in patients with adrenal incidentalomas compared to control subjects.

DESIGN, SETTING AND PARTICIPANTS

A prospective study, 73 patients with adrenal incidentalomas, 21 bilateral and 52 unilateral and 34 matched controls in University Hospital.

METHODS

Collect fasting blood sample before and 60 min after ACTH test (250 µg IV). One week later, perform overnight 1 mg dexamethasone test. The following steroids were measured by liquid chromatography-mass spectrometry (LC-MS): pregnenolone, 17-OH pregnenolone, 17-OH progesterone, 11-deoxycorticosterone, 11-deoxyortisol, 21-deoxycortisol, corticosterone, cortisol, androstenedione and aldosterone.

RESULTS

Mean baseline serum cortisol was higher in incidentalomas, bilateral 361 ± 124, (range 143-665) nmol/L,(p < .0001), unilateral 268 ± 89 3.2 (range 98-507) nmol/L (p < .019) compared to controls 207 ± 100 (range 72-502) nmol/L. ACTH stimulation showed significantly higher levels in bilateral and unilateral cases compared to controls. After dexamethasone, mean serum cortisol levels suppressed in bilaterals 89 ± 69 (range 30-3) nmol/L (p < .0001), 58 ± 52 (range 16-323) nmol/L in unilateral (p < .01) compared to 26 ± 9 (range 7-46) nmol/L in controls. Mean baseline serum corticosterone was higher in bilateral 9.3 ± 4.8 (range 2.4-18.4) nmol/L (p < .005) and unilateral 7.3 ± 5.7 (range 0.1-30.3) nmol/L (p < .01) compared to controls 4.2 ± 2.4 (range 1.1-10.2) nmol/L, after ACTH stimulation significantly increased to higher levels in bilateral (p < .0002) and unilateral cases (p < .044) compared to controls. After dexamethasone, mean levels were 2.5 ± 2.6 (range 0.5-12.5) nmol/L in bilateral (p < .0006), 1.5 ± 1.6 (range 0.3-9.3) nmol/L in unilateral (p < .09) and 0.75 ± 0.46 (range 0.1-2.1) nmol/L in controls. Mean baseline serum 11-deoxycorticosterone (DOC) was higher in bilaterals 0.32 ± 0.23 (range 0.08-1.1) nmol/L (p < .03) compared to controls 0.15 ± 0.21 (range 0.08-1.1) nmol/L. ACTH stimulation increased levels to 3.27 ± 1.72 (range 0.5-7.4) nmol/L in bilateral cases compared to controls 1.369 ± 1.53 (range 0.1-7.1) nmol/L (p < .0001). Dexamethasone decreased levels to baseline (p ns). There were significant differences in serum 21-deoxycortisol (p < .0002) and serum pregnenolone (p < .004) only after ACTH stimulation.

CONCLUSIONS

There is increased activity in several steroid biosynthesis pathways and higher steroid levels in bilateral compared to unilateral cases and evidence of hypercortisolism in 30% unilateral and 62% of bilateral incidentalomas.

Adherence to guidelines for hormonal evaluation in patients with incidentally detected adrenal nodules: effects of radiology report wording and standardized reporting

OBJECTIVE

To compare the rates of hormonal evaluation in patients who had CT reports describing adrenal incidentalomas with and without a specific recommendation for hormonal evaluation.

MATERIALS AND METHODS

We performed a retrospective review of adult outpatients without a history of cancer who had a CT report describing an incidental adrenal nodule. Radiology reports were reviewed to determine whether a standardized macro was used which gave specific recommendations for hormonal evaluation and endocrinology consultation. If no macro was used it was determined whether the report had a recommendation for hormonal evaluation and endocrinology consultation.

RESULTS

A standardized macro recommending hormonal evaluation and endocrinology referral was used in 45/129 (34.8%) reports that described an incidental adrenal nodule. A recommendation for hormonal evaluation was made in 5/84 (6.0%) reports without a macro. Hormonal evaluation was performed in 24/50 (48.0%) patients whose reports recommended it and in 11/79 (13.9%) patients whose reports did not (p < 0.0001). A recommendation for endocrinology referral was made in 2/84 (2.4%) reports without a macro. Patients were seen by endocrinology in 12/47 (25.5%) patients whose reports recommended an endocrinology referral evaluation and 5/82 (6.1%) patients whose reports did not (p < 0.0001). Hormonal evaluation was performed in 17/17 (100%) patients who were seen by endocrinology and 18/112 (16.1%) patients who were not (p < 0.0001). Eleven patients (8.5%) had an evaluation suggesting hyperfunctioning nodules (4 cortisol producing, 6 aldosterone producing, and 1 pheochromocytoma).

CONCLUSIONS

Utilizing standardized macros that make specific recommendations for hormonal evaluation in patients with adrenal incidentalomas leads to improved adherence to clinical guidelines.