Adrenocortical Adenoma Arising from Adrenohepatic Fusion: A Mimic of Hepatocellular Carcinoma-Case Report.

AIM: We present a case of adrenocortical adenoma originating from the adrenohepatic fusion (AHF) region, accompanied by advanced hepatosteatosis in the liver tissue, and discuss its distinction from hepatocellular carcinoma.  Case Experience: A 68-year-old male patient was admitted to the hospital following a fall from a height. He was referred to our hospital after an incidental discovery of a liver mass during an abdominal ultrasound examination. Subsequently, magnetic resonance imaging (MRI) imaging was conducted, followed by segmental liver resection with right adrenalectomy, and histological analysis of a biopsy from the lesion.  Results: Upon histologic examination, the case was determined to be an adrenocortical adenoma originating from the AHF.  Discussion: Adrenohepatic fusion (AHF) denotes the histological amalgamation of cells from the right adrenal cortex and right hepatic parenchyma. Only a limited number of cases of neoplasia originating from this region have been documented. These rare instances often present a diagnostic challenge, with preoperative imaging frequently misidentifying them as primary malignancies of either hepatic or adrenal origin, potentially leading to unnecessary extensive resections. The integration of immunohistochemical staining alongside clinical and radiological data proves helpful for accurately diagnosing this condition.  Conclusion: Awareness among clinicians, radiologists, and pathologists regarding the tumors that may arise from this region can mitigate the risk of performing extensive resections unnecessarily.

Adrenal cortical adenoma arising in the setting of renal-adrenal fusion: a case report and review of the literature.

BACKGROUND: Renal-adrenal fusion is a rare entity resulting from incomplete encapsulation of the adrenal gland and kidney. Only 18 cases have been reported in English literature to date. CASE PRESENTATION: Our patient is a 77-year-old African American female who presented with a systolic blood pressure of 200 mmHg. Computed tomography showed an enhancing 9 × 6 cm mass anterior and medial to the left kidney. The patient underwent a left adrenalectomy with partial nephrectomy. Gross and histologic examinations revealed an adrenal cortical adenoma and renal-adrenal fusion. CONCLUSION: Renal-adrenal fusion may pose a diagnostic challenge, particularly when there is a concurrent adrenal adenoma. It is important to be aware of this uncommon anomaly to avoid misdiagnosis and overtreatment.

Role of computed tomography in predicting adrenal adenomas with cortisol hypersecretion.

OBJECTIVES: To investigate performance of adrenal CT-derived multivariate prediction models in differentiating adenomas with cortisol hypersecretion from the other subtypes. METHODS: This retrospective study included 127 patients who underwent adrenal CT and had a surgically proven adrenal adenoma. Adenoma subtypes were defined according to biochemical test results: Group A, overt cortisol hypersecretion; Group B, mild cortisol hypersecretion; Group C, aldosterone hypersecretion; and Group D, non-function. Two independent readers analyzed size, attenuation, and washout properties of adenomas, and performed quantitative and qualitative analyses for assessing contralateral adrenal atrophy. Actual and internally validated areas under the curves (AUCs) of adrenal CT-derived multivariate prediction models for differentiating adenomas with cortisol hypersecretion from the other subtypes were assessed. RESULTS: In differentiating Group A from the other groups, the actual and internally validated AUCs of the prediction model were 0.856 (95% confidence interval [CI]: 0.786, 0.926) and 0.847 (95% CI: 0.695, 0.999) for Reader 1, respectively, and 0.901 (95% CI: 0.845, 0.956) and 0.897 (95% CI: 0.783, 1.000) for Reader 2, respectively. In differentiating Group B from groups C and D, the actual and internally validated AUCs of the prediction model were 0.777 (95% CI: 0.687, 0.866) and 0.760 (95% CI: 0.552, 0.969) for Reader 1, respectively, and 0.783 (95% CI: 0.690, 0.875) and 0.765 (95% CI: 0.553, 0.977) for Reader 2, respectively. CONCLUSION: Adrenal CT may be useful in differentiating adenomas with cortisol hypersecretion from the other subtypes. ADVANCES IN KNOWLEDGE: Adrenal CT may benefit in adrenal adenoma subtyping.

Feasibility of single-port laparoscopic partial adrenalectomy with selective adrenal venous sampling and high-resolution ultrasound for unilateral aldosterone-producing adenomas.

BACKGROUND: The surgical and endocrinological outcomes of single-port laparoscopic partial adrenalectomy for patients with aldosterone-producing adenomas are unknown. Precise diagnosis of intra-adrenal aldosterone activity and a precise surgical procedure may improve outcomes. In this study, we aimed to determine the surgical and endocrinological outcomes of single-port laparoscopic partial adrenalectomy with preoperative segmental selective adrenal venous sampling and intraoperative high-resolution laparoscopic ultrasound in patients with unilateral aldosterone-producing adenomas. We identified 53 patients with partial adrenalectomy and 29 patients with laparoscopic total adrenalectomy. Single-port surgery was performed for 37 and 19 patients, respectively. METHODS: A single-center, retrospective cohort study. All patients with unilateral aldosterone-producing adenomas diagnosed by selective adrenal venous sampling and treated surgically between January 2012 and February 2015 were included. Follow-up with biochemical and clinical assessments was set at 1 year after surgery for short-term outcomes and was performed every 3 months after surgery. RESULTS: We identified 53 patients with partial adrenalectomy and 29 patients with laparoscopic total adrenalectomy. Single-port surgery was performed for 37 and 19 patients, respectively. Single-port surgery was associated with shorter operative and laparoscopic times (odds ratio, 0.14; 95% confidence interval, 0.039-0.49; P = .002 and odds ratio, 0.13; 95% confidence interval, 0.032-0.57; P = .006, respectively). All single-port and multi-port partial adrenalectomy cases showed complete short-term (median 1 year) biochemical success, and 92.9% (26 of 28 patients) who underwent single-port partial adrenalectomy and 100% (13 of 13 patients) who underwent multi-port partial adrenalectomy showed complete long-term (median 5.5 years) biochemical success. No complications were observed with single-port adrenalectomy. CONCLUSION: Single-port partial adrenalectomy is feasible after selective adrenal venous sampling for unilateral aldosterone-producing adenomas, with shorter operative and laparoscopic times and a high rate of complete biochemical success.

Using CT radiomic features based on machine learning models to subtype adrenal adenoma.

BACKGROUND: Functioning and non-functioning adrenocortical adenoma are two subtypes of benign adrenal adenoma, and their differential diagnosis is crucial. Current diagnostic procedures use an invasive method, adrenal venous sampling, for endocrinologic assessment. METHODS: This study proposes establishing an accurate differential model for subtyping adrenal adenoma using computed tomography (CT) radiomic features and machine learning (ML) methods. Dataset 1 (289 patients with adrenal adenoma) was collected to develop the models, and Dataset 2 (54 patients) was utilized for external validation. Cuboids containing the lesion were cropped from the non-contrast, arterial, and venous phase CT images, and 1,967 features were extracted from each cuboid. Ten discriminative features were selected from each phase or the combined phases. Random forest, support vector machine, logistic regression (LR), Gradient Boosting Machine, and eXtreme Gradient Boosting were used to establish prediction models. RESULTS: The highest accuracies were 72.7%, 72.7%, and 76.1% in the arterial, venous, and non-contrast phases, respectively, when using radiomic features alone with the ML classifier of LR. When features from the three CT phases were combined, the accuracy of LR reached 83.0%. After adding clinical information, the area under the receiver operating characteristic curve increased for all the machine learning methods except for LR. In Dataset 2, the accuracy of LR was the highest, reaching 77.8%. CONCLUSION: The radiomic features of the lesion in three-phase CT images can potentially suggest the functioning or non-functioning nature of adrenal adenoma. The resulting radiomic models can be a non-invasive, low-cost, and rapid method of minimizing unnecessary testing in asymptomatic patients with incidentally discovered adrenal adenoma.

Differentiating between adrenocortical carcinoma and lipid-poor cortical adenoma: A novel cross-sectional imaging-based score.

BACKGROUND: Discrimination between adrenocortical carcinoma and lipid-poor cortical adenoma preoperatively is frequently difficult as these two entities have overlapping imaging characteristics. Differentiation will allow for the selection of the most appropriate operative approach and may help prevent over-treatment. We aimed to identify imaging features that could preoperatively differentiate adrenocortical carcinoma from lipid-poor cortical adenoma and use them in a novel imaging-based score. METHODS: We conducted a retrospective analysis of patients with pathologically proven adrenocortical carcinoma and lipid-poor cortical adenoma who underwent resection in a single tertiary referral center between March 1998 and August 2020. The inclusion criteria were diameter >1 cm, attenuation >10 Hounsfield units on nonenhanced computed tomography, and histopathologic diagnosis. Patients with metastatic or locally advanced adrenocortical carcinoma adenoma (stages 3-4) were excluded. We developed a score using binary logistic multivariate regression model in 5-fold derivation (∼70%) cohorts with stepwise backward conditional regression as feature selection. Standardized mean regression weight was used as variable score points. RESULTS: We identified 232 adrenals resected across 211 patients. By comparing the imaging characteristics of adrenocortical carcinoma (n = 56) and lipid-poor cortical adenoma (n = 156), we revealed statistically significant differences between the groups in 9 parameters: size, attenuation, thin and thick rim enhancement patterns, heterogeneity, calcification, necrosis, fat infiltration, and lymph node prominence. The score mean performance was 100% sensitivity for the exclusion of adrenocortical carcinoma, 80% specificity (95% confidence interval, 68.3-91.5), 66% positive predictive value (95% confidence interval, 52.3-78.7), and 100% negative predictive value with area under the curve of 0.974. CONCLUSION: We defined and evaluated a novel 9-variable, imaging-based score. This score outperformed any single variable and could facilitate safe preoperative discrimination of adrenocortical carcinoma and lipid-poor cortical adenoma.

Dual Energy-Derived Metrics for Differentiating Adrenal Adenomas From Nonadenomas on Single-Phase Contrast-Enhanced CT.

BACKGROUND. Adrenal masses are often indeterminate on single-phase postcontrast CT. Dual-energy CT (DECT) with three-material decomposition algorithms may aid characterization. OBJECTIVE. The purpose of this study was to compare the diagnostic performance of metrics derived from portal venous phase DECT, including virtual noncontrast (VNC) attenuation, fat fraction, iodine density, and relative enhancement ratio, for characterizing adrenal masses. METHODS. This retrospective study included 128 patients (82 women, 46 men; mean age, 64.6 ± 12.7 [SD] years) who between January 2016 and December 2019 underwent portal venous phase abdominopelvic DECT that showed a total of 139 adrenal lesions with an available reference standard based on all imaging, clinical, and pathologic records (87 adenomas, 52 nonadenomas [48 metastases, two adrenal cortical carcinomas, one ganglioneuroma, one hematoma]). Two radiologists placed ROIs to determine the following characteristics of the masses: VNC attenuation, fat fraction, iodine density normalized to portal vein, and for masses with VNC greater than 10 HU, relative enhancement ratio (ratio of portal venous phase attenuation to VNC attenuation). Readers' mean measurements were used for ROC analyses, and clinically optimal thresholds were derived as thresholds yielding the highest sensitivity at 100% specificity. RESULTS. Adenomas and nonadenomas were significantly different (all p < .001) in VNC attenuation (mean ± SD, 18.5 ± 12.9 vs 34.1 ± 8.9 HU), fat fraction (mean ± SD, 24.3% ± 8.2% vs 14.2% ± 5.6%), normalized iodine density (mean ± SD, 0.34 ± 0.15 vs 0.17 ± 0.17), and relative enhancement ratio (mean ± SD, 186% ± 96% vs 58% ± 59%). AUCs for all metrics ranged from 0.81 through 0.91. The metric with highest sensitivity for adenoma at the clinically optimal threshold (i.e., 100% specificity) was fat fraction (threshold, ≥ 23.8%; sensitivity, 59% [95% CI, 48-69%]) followed by VNC attenuation (≤ 15.2 HU; sensitivity, 39% [95% CI, 29-50%]), relative enhancement ratio (≥ 214%; sensitivity, 37% [95% CI, 25-50%]), and normalized iodine density (≥ 0.90; sensitivity, 1% (95% CI, 0-60%]). VNC attenuation at the traditional true noncontrast attenuation threshold of 10 HU or lower had sensitivity of 28% (95% CI, 19-38%) and 100% specificity. Presence of fat fraction 23.8% or greater or relative enhancement ratio 214% or greater yielded sensitivity of 68% (95% CI, 57-77%) with 100% specificity. CONCLUSION. For adrenal lesions evaluated with single-phase DECT, fat fraction had higher sensitivity than VNC attenuation at both the clinically optimal threshold and the traditional threshold of 10 HU or lower. CLINICAL IMPACT. By helping to definitively diagnose adenomas, DECT-derived metrics can help avoid downstream imaging for incidental adrenal lesions.

68Ga-DOTATATE PET/CT of ACTH-Independent Cushing Syndrome Due to Ectopic Adrenocortical Adenoma.

ABSTRACT: Adrenocorticotropic hormone-independent Cushing syndrome due to ectopic adrenocortical adenoma is a very rare entity. We herein present a case of a 57-year-old woman who was referred to our hospital with persistent Cushing syndrome after undergoing unnecessary laparoscopic left adrenalectomy. 68Ga-DOTATATE PET/CT revealed increased uptake in the nodule in the right hilum, which was histologically confirmed to be ectopic adrenocortical adenoma. Removal of the tumor was followed by the disappearance of clinical symptoms of Cushing syndrome. In this case, 68Ga-DOTATATE PET/CT contributed to the diagnosis of ectopic adrenocortical adenoma.

Differential diagnostic value of plain CT scan in adrenal adenoma and non-adenoma: A two-center control study of mean attenuation value, minimum attenuation value, and CT histogram.

Objectives: To investigate the value of mean attenuation value (AVmean), minimum attenuation value (AVmin), and CT histogram (CTH) for the differential diagnosis of adrenal adenoma and non-adenoma in two medical centers. Methods: The plain CT data of 403 cases of adrenal adenoma and 141 cases of non-adenoma in center A were retrospectively analyzed, and compared with data of 86 cases of adenoma and 71 cases of non-adenoma in center B. All cases were confirmed by pathology or clinical follow-up. The diagnostic efficacy of AVmean ≤ 10 Hounsfield units (HU), AVmin ≤ 0 HU, and CTH negative pixels ≥ 10% for adrenal adenoma, and AVmin and CTH for adenoma with AVmean > 10Hu were compared between the two medical centers. Results: In medical centers A and B, the AUC of AVmean for the differential diagnosis of adenoma and non-adenoma was 0.956 and 0.956, respectively, and the corresponding sensitivity, specificity, and accuracy were, 0.591 and 0.663, 1.000 and 1.000, 0.697, and 0.815, respectively, when the threshold was ≤ 10 HU. The AUC of AVmin was 0.941 and 0.958, respectively, and the corresponding sensitivity, specificity, and accuracy were 0.869 and 0.826, 0.986, and 0.972, 0.899, and 0.892, respectively, when the threshold was ≤ 0 HU. The AUC of CTH negative pixels was 0.948 and 0.952, respectively, and the corresponding sensitivity, specificity, and accuracy were 0.759 and 0.674, 1.000 and 1.000, 0.822, and 0.822, respectively, when the threshold was ≥ 10%. Among adenoma with AVmean >10 HU, the best threshold of AVmin in center A and center B were -0.250HU and 2.375HU, and the corresponding AUC, sensitivity and specificity were 0.858 and 0.846, 0.691 and 0.586, 0.986 and 0.958; the best threshold of CTH in center A and center B were 0.895% and 0.775%, and the corresponding AUC, sensitivity and specificity were 0.873 and 0.822, 0.818 and 0.724, 0.837 and 0.915. Conclusion: AVmean, AVmin, and CTH are all important parameters for differentiating adrenal adenoma from non-adenoma. Even for adenomas with AVmean > 10 HU, AVmin and CTH still had high diagnostic efficiency. The three parameters are complementary, assisting clinicians to develop personalized treatments.

Oncocytic adrenocortical tumour presenting as an incidentaloma: a diagnostic challenge.

Oncocytic adrenocortical neoplasms are a rare histopathological subtype of adrenal tumours which are usually benign and, if malignant, are less likely to metastasise. We report a case of a non-functioning oncocytic adrenocortical tumour, identified incidentally in a middle-aged woman. It was initially reported as a left-sided 3.5×3.4×5.6 cm adrenal adenoma. It however increased in size to 5.4×4.0×4.3 cm on follow-up scans. Subsequent review of the scans revealed an indeterminate lesion with a precontrast density of 30 Hounsfield units, an absolute washout of 42.6% and a relative washout of 28.6%. As a result, laparoscopic left adrenalectomy was performed. Histology confirmed oncocytic adrenocortical carcinoma when using the Lin-Weiss-Bisceglia system, though it was deemed benign when using the Helsinki scoring system. There has been no evidence of recurrence to date. This case highlights the potential pitfalls in the diagnosis of oncocytic neoplasms and the increased specificity of the Helsinki score in assessing metastatic potential.

Evaluation of the T2-weighted (T2W) adrenal MRI calculator to differentiate adrenal pheochromocytoma from lipid-poor adrenal adenoma.

OBJECTIVES: To evaluate the T2-weighted (T2W) MRI calculator to differentiate adrenal pheochromocytoma from lipid-poor adrenal adenoma. METHODS: Twenty-nine consecutive pheochromocytomas resected between 2010 and 2019 were compared to 23 consecutive lipid-poor adrenal adenomas. Three blinded radiologists (R1, R2, R3) subjectively evaluated T2W signal intensity and heterogeneity and extracted T2W signal intensity ratio (SIR) and entropy. These values were imputed into a quantitative and qualitative T2W adrenal MRI calculator (logistic regression model encompassing T2W SIR + entropy and subjective SI [relative to renal cortex] and heterogeneity) using a predefined threshold to differentiate metastases from adenoma and accuracy derived by a 2 × 2 table analysis. RESULTS: Subjectively, pheochromocytomas were brighter (p < 0.001) and more heterogeneous (p < 0.001) for all three radiologists. Inter-observer agreement was fair-to-moderate for T2W signal intensity (K = 0.37-0.46) and fair for heterogeneity (K = 0.24-0.32). Pheochromocytoma had higher T2W-SI-ratio (p < 0.001) and entropy (p < 0.001) for all three readers. The quantitative calculator differentiated pheochromocytoma from adenoma with high sensitivity, specificity, and accuracy (100% [95% confidence intervals 88-100%], 87% [66-97%], and 94% [86-100%] R1; 93% [77-99%], 96% [78-100%], and 94% [88-100%] R2; 97% [82-100%], 96% [78-100%], and 96% [91-100% R3]). The qualitative calculator was specific with lower sensitivity and overall accuracy (48% [29-68%], 100% [85-100%], and 74% [65-83%] R1; 45% [26-64%], 100% [85-100%], and 72% [63-82%] R2; 59% [39-77%], 100% [85-100%], and 79% [70-88% R3]). CONCLUSIONS: T2W signal intensity and heterogeneity differ, subjectively and quantitatively, in pheochromocytoma compared to adenoma. Use of a quantitative T2W adrenal calculator which combines T2W signal intensity ratio and entropy was highly accurate to diagnose pheochromocytoma outperforming subjective analysis. KEY POINTS: • Pheochromocytomas have higher T2-weighted signal intensity and are more heterogeneous compared to lipid-poor adrenal adenomas evaluated subjectively and quantitatively. • The quantitative T2-weighted adrenal MRI calculator, a logistic regression model combining T2-weighted signal intensity ratio and entropy, is highly accurate for diagnosis of pheochromocytoma. • The qualitative T2-weighed adrenal MRI calculator had high specificity but lower sensitivity and overall accuracy compared to quantitative assessment and agreement was only fair-to-moderate.

Inter-individual comparison of diagnostic accuracy of adrenal washout CT compared to chemical shift MRI plus the T2-weighted (T2W) adrenal MRI calculator in indeterminate adrenal masses: a retrospective non-inferiority study.

OBJECTIVE: To compare diagnostic accuracy of washout (WO)-CT to chemical shift (CS)-MRI + T2W adrenal MRI Calculator (T2W-Calculator) to diagnose adrenal adenoma in indeterminate adrenal masses. METHODS: This retrospective, cross-sectional, non-inferiority study evaluated 40 consecutive indeterminate adrenal masses; each with WO-CT and MRI. Two blinded radiologists independently evaluated in mixed order: pre-contrast attenuation (Hounsfield Units, HU) and absolute WO ([Peak.HU-Delay.HU]/[Peak.HU-Pre.HU] × 100%), Chemical Shift Signal Intensity (CS-SI) Index, T2W SI ratio, and Entropy (which were imputed into the T2W-Calculator). Diagnostic accuracy for adrenal adenoma was tabulated using 2 × 2 tables. True -positive diagnoses of adenoma were CT = Pre-HU < 10 or absolute WO ≥ 60%, MRI = SI index ≥ 16.5% or T2W-Calculator < 0.631. RESULTS: There were 73% (29/40) adenomas and 27% (11/40) other masses (5 pheochromocytoma, 3 solitary fibrous tumor, 1 metastasis, 1 cavernous hemangioma, and 1 adrenocortical carcinoma). Sensitivity, specificity, and accuracy for diagnosis of adenoma using CT-WO were 78% (95% confidence intervals [CI] 56-93%), 35% (14-62%), and 57% (42-71%) Reader 1 and 72% (53-87%), 46% (17-77%), and 59% (41-76%) Reader 2. Sensitivity, specificity, and accuracy for diagnosis of adenoma using MRI were 100% (88-100%), 64% (34-90%), and 82% (67-97%) Reader 1 and 86% (68-96%), 73% (39-94%), and 80% (64-95%) Reader 2. MRI had higher overall accuracy (p = 0.02 Reader 1, 0.05 Reader 2) compared to CT-WO. CONCLUSION: Chemical shift MRI combined with the T2W adrenal MRI calculator is not inferior to CT Washout for diagnosis of adrenal adenoma among indeterminate adrenal masses.

Adrenocortical adenoma manifesting as Cushing's syndrome and pseudo-precocious puberty in a toddler.

Cushing's syndrome is a rare disease in the paediatric age group. Adrenocortical carcinomas (ACC) constitute the most common cause of Cushing's syndrome between 1 and 5 years of age. Often, adrenocortical carcinomas co-secrete other hormones such as androgens (testosterone), deoxy-corticosterone (DOCA), or 17-hydroxy-progesterone [17(OH)P] in addition to cortisol. This may manifest with symptoms and signs of precocious puberty along with Cushing's syndrome. It is rare for a benign adrenocortical adenoma to co-secrete androgens and other hormones in addition to cortisol. Differentiation between adenoma and carcinoma is difficult in all aspects: clinical, radiological, and histopathological. Here, we describe the case of a 2.5-year-old male child who presented with Cushing's syndrome and virilization. Although we suspected ACC clinically, the radiological and histopathological findings were suggestive of benign adrenocortical adenoma. Our case represents the diagnostic challenge that exists in paediatric adrenocortical tumours.

Discriminative Capacity of CT Volumetry to Identify Autonomous Cortisol Secretion in Incidental Adrenal Adenomas.

CONTEXT: Incidentally discovered adrenal adenomas are common. Assessment for possible autonomous cortisol excess (ACS) is warranted for all adrenal adenomas, given the association with increased cardiometabolic disease. OBJECTIVE: To evaluate the discriminatory capacity of 3-dimensional volumetry on computed tomography (CT) to identify ACS. METHODS: Two radiologists, blinded to hormonal levels, prospectively analyzed CT images of 149 adult patients with unilateral, incidentally discovered, adrenal adenomas. Diameter and volumetry of the adenoma, volumetry of the contralateral adrenal gland, and the adenoma volume-to-contralateral gland volume (AV/CV) ratio were measured. ACS was defined as cortisol ≥ 1.8 mcg/dL after 1-mg dexamethasone suppression test (DST) and a morning ACTH ≤ 15. pg/mL. RESULTS: We observed that ACS was diagnosed in 35 (23.4%) patients. Cortisol post-DST was positively correlated with adenoma diameter and volume, and inversely correlated with contralateral adrenal gland volume. Cortisol post-DST was positively correlated with the AV/CV ratio (r = 0.46, P < 0.001) and ACTH was inversely correlated (r = -0.28, P < 0.001). The AV/CV ratio displayed the highest odds ratio (1.40; 95% CI, 1.18-1.65) and area under curve (0.91; 95% CI, 0.86-0.96) for predicting ACS. An AV/CV ratio ≥ 1 (48% of the cohort) had a sensitivity of 97% and a specificity of 70% to identify ACS. CONCLUSION: CT volumetry of adrenal adenomas and contralateral adrenal glands has a high discriminatory capacity to identify ACS. The combination of this simple and low-cost radiological phenotyping can supplement biochemical testing to substantially improve the identification of ACS.

Dual-energy spectral detector computed tomography differential diagnosis of adrenal adenoma and pheochromocytoma: Changes in the energy level curve, a phenomenon caused by lipid components?

Background and objectives: Pheochromocytoma and adrenal adenoma are common space-occupying lesions of the adrenal gland, and incorrect surgery may lead to adrenal crisis. We used a new method, dual-energy spectral detector computed tomography (SDCT), to differentiate between the two. Materials and methods: We analysed the imaging images of patients with SDCT scans and pathologically confirmed adrenal adenomas (n=70) and pheochromocytomas (n=15). The 40, 70, and 100 KeV virtual monoenergetic images (VMIs) were reconstructed based on the SCDT arterial phase, and the correlation between the arterial/venous phase iodine concentration (AP-IC/VP-IC), the effective atomic number (Z-effect), the slope of the Hounsfield unit attenuation plot (VMI slope) and the pathological results was tested. The Shapiro-Wilk test was used to determine whether the above data conformed to a normal distribution. For parameters with P greater than 0.05, Student's t test was used, and the Mann-Whitney test was used for the remaining parameters. A ROC curve was drawn based on the results. Results: Student's t test showed that the 40 KeV VMI and the VMI slope were both statistically significant (P<0.01). The Mann-Whitney U test showed that ID-A was statistically significant (P=0.004). ROC curve analysis showed that 40 keV VMI (AUC=0.818), AP-IC (AUC=0.736), difference (AUC=0.817) and VMI-Slope (0.817) could be used to differentiate adrenal adenoma from pheochromocytoma. Conclusion: The effect of lipid components on SDCT parameters can be used to differentiate adrenal adenoma from pheochromocytoma.

Imaging features of atypical adrenocortical adenomas: a radiological-pathological correlation.

OBJECTIVE: Adrenal adenomas are frequently picked up incidentally on cross-sectional imaging and are known to have a classic imaging appearance on CT and MRI. However, not all adrenal adenomas have this typical radiologic appearance. Our aim is to present the radiological features of atypical adrenocortical adenomas with pathological correlation. METHODS: All the imaging from the pathologically proven adrenal adenoma cases in our hospital (Tallaght University Hospital, Dublin, Ireland) database (from 2004 to 2019) was reviewed. 8 out of 48 cases (16%) had an atypical radiological appearance and were selected for presentation. RESULTS: Eight cases demonstrated atypical radiological features including heterogeneous density, incomplete washout on post-contrast imaging, the presence of macroscopic fat and calcification. Lipomatous metaplasia was present in two of the cases pathologically. CONCLUSION: Adrenocortical adenomas are the most common adrenal mass encountered on CT, however, may not always have classic imaging features. Radiologists should be familiar with both the typical and atypical imaging manifestations of these benign adrenal lesions. ADVANCES IN KNOWLEDGE: This paper comprehensively describes the atypical features of adrenocortical adenomas with case examples and radiologic-pathologic correlation. Guidelines and an approach to the work-up of adrenal lesions with atypical appearances are also provided.

CT-based Abdominal Adipose Tissue Area Changes in Patients Undergoing Adrenalectomy Due to Cushing's Syndrome and Non-functioning Adenomas.

BACKGROUND: The majority of Cushing's syndrome (CS) cases constitute patients with functional adrenal adenomas. In adrenal CS, visceral adipose tissue (VAT) area, VAT/subcutaneous adipose tissue (SAT), and VAT/total adipose tissue (TAT) ratios are expected to decrease in response to adrenalectomy, although no change is expected in non-functioning adrenal adenomas (NFA). OBJECTIVE: To evaluate the changes in VAT, SAT, TAT areas and VAT/SAT, VAT/TAT ratios using computed tomography (CT) in patients who underwent adrenalectomy due to adenomas. METHODS: Preoperative and postoperative CT of 32 patients (16 with CS and 16 with NFA) were retrospectively evaluated. The VAT, SAT, TAT areas were obtained from CT at the level of L1-2 intervertebral disc space, and the VAT/SAT, VAT/TAT ratios were calculated. The postoperative parameter changes in both groups were evaluated compared to the preoperative values. The level of statistical significance was considered as p<0.05. RESULTS: The time interval between preoperative and postoperative CT measurements were 10.37 months (6-17) in CS and 9.75 months (7-15) in NFA groups (p=073). Preoperative CT indicated that the patients with CS had larger VAT and TAT areas (p=0.03, p=0.02) but SAT remained unchanged (p=0.08). However, postoperative CT revealed that there was no difference between the two groups in terms of VAT, TAT, and SAT areas (p=0.87, p=0.36, p=0.14). Postoperatively, in patients with CS, there was a decrease in VAT and TAT areas (p=0.01 for both) and VAT/SAT and VAT/TAT ratios (p=0.03, p=0.02) but SAT remained unchanged (p=0.10). In patients with NFA, no change was detected in the postoperative SAT, TAT, and VAT areas (p=0.12, p=0.40, p=0.99) or the VAT/SAT and VAT/TAT ratios (p=0.38, p=0.62). CONCLUSIONS: Adrenalectomy is an effective treatment method leading to a decrease in the VAT, TAT areas, and VAT/SAT and VAT/TAT ratios in patients with cortisol producing adrenocortical adenoma. Thus, CT facilitates quantitative demonstration of the changes while evaluating the response of these patients to treatment.

Imaging characteristics of pathologically proven adrenal adenomas with myelolipomatous degeneration: correlation with clinical and pathologic features.

OBJECTIVES: Adrenal adenoma with myelolipomatous degeneration (AMD) is a rarely reported and often overlooked entity. The aim of this study is to improve understanding of these lesions by characterizing the imaging findings with pathologic and clinical correlation. METHODS: In the largest series to date, we report 11 nodules in 11 patients confirmed with a pathologic diagnosis of AMD. The available cross-sectional imaging and histopathologic features were reviewed by two radiologists and two pathologists, respectively. Clinical and laboratory data for each patient were obtained from the electronic medical records, when available. RESULTS: All 11 patients had a CT prior to resection or biopsy of the adrenal nodule, with five having received an adrenal mass protocol study. An MRI was available in three patients. The median size of the nodules on imaging was 4.5 cm (range 2.8-8.7) and all but one had macroscopic fat. The largest focus of macroscopic fat had a median size of 0.7 cm (range 0.2-1.6) and on average was 14.4% the size of the tumor, using greatest dimensions. Four (36.4%) patients had a diagnosis of Cushing syndrome prior to nodule resection. CONCLUSIONS: Not all adrenal nodules with macroscopic fat on imaging are pure myelolipomas. An AMD should be considered, especially if the foci of fat are small and other features of an adenoma are present. Some may also be associated with Cushing syndrome. ADVANCES IN KNOWLEDGE: Myelolipomatous degeneration within an adrenal adenoma has only rarely been previously reported with very few reports emphasizing the imaging features. There may be an association with cortisol hypersecretion and improved recognition of this entity could lead to changes in clinical management.