Differentiation between benign and malignant adrenal mass using contrast-enhanced ultrasound

Contrast-enhanced ultrasound appearance of adrenal hemorrhage after orthotopic liver transplantation: a retrospective study

OBJECTIVES

This study aimed to identify the incidence of adrenal hemorrhage (AH) after OLT and to summarize the ultrasound (US) and contrast-enhanced ultrasound (CEUS) characteristics.

METHODS

Patients with adrenal lesions after OLT at our hospital were retrospectively reviewed between January 2010 and November 2023. The reference diagnosis was defined on the basis of surgical data, computed tomography scans, and magnetic resonance imaging with at least 12 months of follow-up. The incidence of AH and the US and CEUS characteristics after OLT were analyzed and compared with those of adrenal metastases.

RESULTS

A total of 23 patients (1.2%) with AH and 7 patients (0.35%) with suprarenal metastases were assessed. Compared with metastases, hematomas had more inhomogeneous echotextures (57% vs. 0.00%, P = 0.010), hypoechoic or mixed-echoic patterns (96% vs. 71%, P = 0.022), and anechoic areas (52% vs. 0.00%, P = 0.024), and their echotextures varied more over time (65% vs. 0.14%, P = 0.031). CEUS was performed on 12 patients with AH and 2 patients with metastases. A "jet-like" contrast superflux was observed in one actively bleeding hematoma, whereas no enhancement was observed in any static hematoma (100%). However, adrenal metastases had a contrast-enhanced appearance in the early arterial phase, followed by fast washout in the late phase (100%), and the difference was statistically significant (P < 0.001).

CONCLUSION

The sonographic characteristics of AH after OLT vary over time. CEUS is recommended when adrenal lesions are detected, as CEUS can differentiate AH from metastases.

Adrenal Lesions: A Review of Imaging

Adrenal lesions are frequently incidentally diagnosed during investigations for other clinical conditions. Despite being usually benign, nonfunctioning, and silent, they can occasionally cause discomfort or be responsible for various clinical conditions due to hormonal dysregulation; therefore, their characterization is of paramount importance for establishing the best therapeutic strategy. Imaging techniques such as ultrasound, computed tomography, magnetic resonance, and PET-TC, providing anatomical and functional information, play a central role in the diagnostic workup, allowing clinicians and surgeons to choose the optimal lesion management. This review aims at providing an overview of the most encountered adrenal lesions, both benign and malignant, including describing their imaging characteristics.

Contrast-enhanced ultrasound of the kidneys and adrenals in children

Pediatric applications of contrast-enhanced ultrasound (CEUS) are growing. Evaluation of the kidneys and adrenal glands in children using intravenous administration of US contrast agents, however, is still an off-label indication. Pediatric CEUS applications for kidneys are similar to those in adults, including ischemic disorders, pseudo- versus real tumors, indeterminate lesions, complex cystic lesions, complicated pyelonephritis, and abscesses. CEUS applications for evaluation of adrenal glands in children are limited, mainly focusing on the assessment and follow-up of adrenal trauma and the differentiation between an adrenal hemorrhage and a mass. This review addresses the current experience in pediatric CEUS of the kidneys and adrenal glands. By extrapolating the established knowledge for US contrast evaluations in the adult kidney to the pediatric context we can note opportunities for CEUS clinical use in children.

[Adrenal imaging: anatomy and pathology (literature review)]

This literature review focuses on the normal adrenal gland anatomy and typical imaging features necessary to evaluate benign and malignant lesions. In particular, adenoma, pheochromocytoma, metastases and adrenocortical carcinoma were discussed as some of the most common lesions. For this purpose, a review of relevant local and international literature sources up to January 2021 was conducted.In many cases, adrenal incidentalomas have distinctive features allowing characterization using noninvasive methods. It is possible to suspect a malignant nature and promptly refer the patient for the necessary invasive examinations in some cases. -Computed tomography, especially with intravenous contrast enhancement, is the primary imaging modality because it enables differential diagnosis. Magnetic resonance tomography remains a sensitive method in lesion detection and follow-up but is not very specific for determining the malignant potential. Positron emission computed tomography also remains an additional method and is used mainly for differential diagnosis of malignant tumors, detecting metastases and recurrences after surgical treatment. Ultrasound has a limited role but is nevertheless of great importance in the pediatric population, especially newborns. Promising techniques such as radiomics and dual-energy CT can expand imaging capabilities and improve diagnostic accuracy.Because adrenal lesions are often incidentally detected by imaging performed for other reasons, it is vital to interpret such findings correctly. This review should give the reader a broad overview of how different imaging modalities can evaluate adrenal pathology and guide radiologists and clinicians.

Contrast-enhanced ultrasound in evaluation of adrenal lesions with CT/MRI correlation

Most of the adrenal masses are incidentally detected. Multiphasic CT forms the mainstay for diagnosis and characterization of adrenal masses. MRI can further be used if the masses are indeterminate on CT scan. But as these investigations are expensive with risk of radiation exposure, contrast-enhanced ultrasound (CEUS) is currently under evaluation to assess its utility to act as a screening modality to differentiate benign vs malignant adrenal masses This investigative modality is relatively safe and can be used in patients having renal dysfunction or allergy to CT contrast. We, hereby, present a pictorial review of imaging appearance of various adrenal lesions on CEUS with CT and MRI correlation.

Utility of contrast-enhanced ultrasound in differential diagnosis of adrenal tumors in dogs

This prospective case study aimed to clarify the clinical significance of contrast-enhanced ultrasound (CEUS) for the differential diagnosis of canine adrenal tumors. Forty-three client-owned dogs with adrenal tumors were included. All dogs underwent CEUS, which was evaluated qualitatively and quantitatively. The peak signal intensity (PI), time to peak signal intensity (TPI), mean transit time (MTT), upslope, and downslope were calculated for each time-intensity curve. The histopathological diagnosis of each resected mass was compared with the CEUS findings and parameters. Enhancement distribution, vascularity, tortuous nourishing vessels, enhancement pattern, and late-phase enhancement did not differ significantly between adrenal cortical adenoma (CA), adenocarcinoma (CAC), and pheochromocytoma (PHEO) in qualitative assessment. In PHEO, the TPI was significantly more rapid compared with that in CA (P=0.0287) and CAC (P=0.0404). The MTT in PHEO was significantly shorter than that in CA (P=0.0016) and CAC (P=0.0003). Upslope in PHEO was larger than that in CAC (P=0.0406). Downslope in PHEO was significantly larger than that in CA (P=0.0048) and CAC (P=0.0018). A receiver operating characteristic curve analysis demonstrated that the area under the MTT curve yielded 0.91 for distinguishing PHEO from adrenocortical tumors in dogs; an MTT cut-off value less than 6,225 msec yielded a sensitivity of 69%, specificity of 94%, and likelihood ratio of 12.46. CEUS appears to be clinically applicable for the differential diagnosis between cortical and medullary origins of primary adrenal tumors in dogs.

Natural History and Management of Familial Paraganglioma Syndrome Type 1: Long-Term Data from a Large Family

Head and neck paragangliomas are the most common clinical features of familial paraganglioma syndrome type 1 caused by succinate dehydrogenase complex subunit D (SDHD) mutation. The clinical management of this syndrome is still unclear. In this study we propose a diagnostic algorithm for SDHD mutation carriers based on our family case series and literature review. After genetic diagnosis, first evaluation should include biochemical examination and whole-body imaging. In case of lesion detection, nuclear medicine examination is required for staging and tumor characterization. The study summarizes the diagnostic accuracy of different functional imaging techniques in SDHD mutation carriers. 18F-3,4-dihydroxyphenylalanine (18F-DOPA) positron emission tomography (PET)-computed tomography (CT) is considered the gold standard. If it is not available, 123I-Metaiodobenzylguanidine (MIBG) could be used also for predicting response to radiometabolic therapy. 18F-fluoro-2-deoxy-D-glucose (18F-FDG) PET-CT has a prognostic role since high uptake identifies more aggressive cases. Finally, 68Ga-peptides PET-CT is a promising diagnostic technique, demonstrating the best diagnostic accuracy in our and in other published case series, even if this finding still needs to be confirmed in larger studies. Periodic follow-up should consist of annual biochemical and ultrasonographic screening and biannual magnetic resonance examination to identify biochemical silent tumors early.

WFUMB position paper on the management incidental findings: adrenal incidentaloma

Focal lesions of the adrenal glands are incidentally detected in approximately 5% of cases by modern imaging techniques. Fewer than 5% of these adrenal incidentalomas are malignant and approximately 10% have endocrine activity. Reliable differentiation of malignant versus benign and hormonally active versus nonfunctional adrenal incidentalomas significantly influences therapeutic management and the outcome of affected individuals. Therefore, each adrenal incidentaloma should undergo a standardized diagnostic work-up to exclude malignancy and endocrine activity. This position statement of the World Federation of Ultrasound in Medicine and Biology (WFUMB) summarizes the available evidence on the management of adrenal incidentaloma and describes efficient management strategies with particular reference to the role of ultrasound techniques.

Comparison of Adrenal Tumor Size in Ultrasound Examinations with and without the Use of a Contrast Agent

Background and objectives: Patients diagnosed with incidentally found adrenal tumors (incidentaloma) that do not meet the criteria for surgical treatment require follow-ups with repeated imaging. The aim of this study is to compare the accuracy of the measurements of the adrenal tumor size in ultrasound (US) with and without contrast in comparison to computed tomography (CT) or magnetic resonance (MRI). Further, this study attempts to answer the question of whether contrast-enhanced ultrasound (CEUS) can improve imaging accuracy and replace CT/MRI in the monitoring of patients with adrenal tumors. Materials and Methods: The retrospective analysis included 79 adult patients with adrenal incidentalomas not exceeding a dimension of 6 cm who underwent a CT or MRI scan, US, and CEUS with the use of SonoVue in two-dimensional (2D) and three-dimensional (3D) projections and Doppler techniques. Tumor vascularization in CEUS was classified as follows: peripheral, peripheral-central, central, or poor. Results: Of 79 adrenal tumors, 48.1% showed peripheral, 29.1% showed poor, 21.5% showed peripheral-central, and only 1.3% showed central vascularization. The median volume of tumors detected with CEUS (69.9 cm³) was significantly higher than with US (44.5 cm³) and CT or MRI (57.1 cm³). The relative error of the adrenal volume with CEUS compared with CT or MRI was significantly higher than with standard US, regardless of the type of tumor vascularization. Conclusions: CEUS does not improve the accuracy of adrenal tumor size assessment regardless of the type of vascularization.

Imaging features of adrenal masses

The widespread use of imaging examinations has increased the detection of incidental adrenal lesions, which are mostly benign and non-functioning adenomas. The differentiation of a benign from a malignant adrenal mass can be crucial especially in oncology patients since it would greatly affect treatment and prognosis. In this setting, imaging plays a key role in the detection and characterization of adrenal lesions, with several imaging tools which can be employed by radiologists. A thorough knowledge of the imaging features of adrenal masses is essential to better characterize these lesions, avoiding a misinterpretation of imaging findings, which frequently overlap between benign and malignant conditions, thus helping clinicians and surgeons in the management of patients. The purpose of this paper is to provide an overview of the main imaging features of adrenal masses and tumor-like conditions recalling the strengths and weaknesses of imaging modalities commonly used in adrenal imaging.

Laparoscopic Trans-Abdominal Right Adrenalectomy for a Large Primitive Adrenal Oncocytic Carcinoma: A Case Report and Review of Literature

Patient: Male, 48

Final Diagnosis: Adrenal oncocytic carcinoma

Symptoms: Asymptomatic

Medication: —

Clinical Procedure: Transabdominal laparoscopic right adrenalectomy

Specialty: Surgery

Dynamic contrast-enhanced endoscopic ultrasound: A quantification method

Dynamic contrast-enhanced ultrasound (DCE-US) has been recently standardized by guidelines and recommendations. The European Federation of Societies for US in Medicine and Biology position paper describes the use for DCE-US. Comparatively, little is known about the use of contrast-enhanced endoscopic US (CE-EUS). This current paper reviews and discusses the clinical use of CE-EUS and DCE-US. The most important clinical use of DCE-US is the prediction of tumor response to new drugs against vascular angioneogenesis.

Pediatric adrenal trauma: evaluation and follow-up with contrast-enhanced ultrasound (CEUS)

Adrenal trauma is rarely encountered in the pediatric population, often as a component of multi-organ injury and often presenting with hematoma formation. Contrast-enhanced computed tomography (CECT) is the established imaging modality both for initial evaluation and follow-up of patients with blunt abdominal trauma. In children, radiation exposure should be minimized and alternative imaging strategies are needed. Contrast-enhanced ultrasound (CEUS) has recently been successfully used for evaluation of patients with hepatic, renal and splenic injury. We present three cases of children with post-traumatic adrenal hematomas, which were initially diagnosed with CECT and subsequently followed up with CEUS, suggesting that CEUS may be considered for follow-up of adrenal injuries in children. CEUS improves the diagnostic capabilities by increasing tissue contrast and spatial resolution, readily differentiating viable from necrotic tissue in comparison to conventional ultrasound without the risk of iodine contrast agents and ionizing radiation of repeated CECT examinations.

Enhancing the role of paediatric ultrasound with microbubbles: a review of intravenous applications

Contrast-enhanced ultrasound (CEUS) represents a complementary technique to greyscale and colour Doppler ultrasonography which allows for real-time visualization and characterization of tissue perfusion. Its inherent advantages in the child makes ultrasonography an ideal imaging modality; repeatability and good tolerance along with the avoidance of CT, a source of ionizing radiation, renders ultrasonography imaging desirable. Although currently paediatric CEUS is principally used in an "off-label" manner, ultrasonography contrast agents have received regulatory approval for assessment of paediatric focal liver lesions (FLL) in the USA. The safety of ultrasound contrast-agents is well documented in adults, as safe as or even surpassing the safety profile of CT and MR contrast agents. Except for the established intracavitary use of CEUS in voiding urosonography, i.v. paediatric applications have been introduced with promising results in the abdominal trauma initial diagnosis and follow-up, characterization and differential diagnosis of FLL and characterization of lung, pleura, renal and splenic pathology. CEUS has also been used to detect complications after paediatric transplantation, evaluate inflammatory bowel disease activity and assess tumour response to antiangiogenic therapy. The purpose of this review was to present these novel i.v. paediatric applications of CEUS and discuss their value.

Use of Contrast-Enhanced Ultrasound in the Differential Diagnosis of Adrenal Tumors in Dogs

We evaluated the diagnostic accuracy of the contrast-enhanced ultrasonography (CEUS), using a second-generation microbubble contrast agent, in differentiating the different types of adrenal mass lesions in 24 dogs. At B-mode ultrasound, 9 lesions involved the right adrenal gland, 14 the left, and 1 was bilateral. Each dog received a bolus of the contrast agent into the cephalic vein, immediately followed by a 5-mL saline flush. The first contrast enhancement of each adrenal lesion was evaluated qualitatively to assess the degree of enhancement and its distribution during the wash-in and wash-out phases, as well as the presence of non-vascularized areas and specific vascular patterns. Pathological diagnoses were determined in all dogs by histopathology or by cytology. Combining enhancement degree and vascularity resulted in the best predictive model, allowing CEUS to differentiate adrenocortical adenoma (n=10), adenocarcinoma (n=7), and pheochromocytoma (n=7) with an accuracy of 91.7% (P &lt; 0.001). Combining enhancement degree and vascularity, CEUS can discriminate malignant versus benign adrenal lesions with a sensitivity of 100.0%, a specificity of 80.0%, and an accuracy of 91.7% (P &lt; 0.001). In conclusion, results of this study confirm that CEUS is useful for differentiating between the different types of adrenal tumors in dogs.

Application of parametric ultrasound contrast agent perfusion studies for differentiation of hyperplastic adrenal nodules from adenomas-Initial study

OBJECTIVES

To evaluate the possibilities of differentiation of non-malignant adrenal masses with the application of the new technique for the evaluation of enhancement after administration of an ultrasound contrast agent: parametric imaging.

PATIENTS AND METHODS

34 non-malignant adrenal masses in 29 patients were evaluated in a dynamic examination after the administration of ultrasound contrast agent with parametric imaging. Patterns on parametric imaging of arrival time were evaluated. The final diagnosis was based on CT, MRI, biochemical studies, follow up and/or histopathology examination.

RESULTS

The study included: 12 adenomas, 10 hyperplastic nodules, 7 myelolipomas, 3 pheochromocytomas, hemangioma with hemorrhage and cyst. The pattern of peripheral laminar inflow of Sonovue on parametric images of arrival time of was 100% sensitive for hyperplastic nodules and 83% specific in regard to adenomas.

CONCLUSIONS

Parametric contrast enhanced ultrasound may accurately differentiate hyperplastic adrenal nodules from adenomas and could be complementary to CT or MRI. Incorporation of perfusion studies to CT or MRI could possibly enable one-shop complete characterization of adrenal masses. This could deliver additional information in diagnostics of patients with Conn Syndrome and warrants further studies in this cohort of patients.

Dynamic contrast-enhanced ultrasound for quantification of tissue perfusion

Dynamic contrast-enhanced ultrasound (US) imaging, a technique that uses microbubble contrast agents with diagnostic US, has recently been technically summarized and reviewed by a European Federation of Societies for Ultrasound in Medicine and Biology position paper. However, the practical applications of this imaging technique were not included. This article reviews and discusses the published literature on the clinical use of dynamic contrast-enhanced US. This review finds that dynamic contrast-enhanced US imaging is the most sensitive cross-sectional real-time method for measuring the perfusion of parenchymatous organs noninvasively. It can measure parenchymal perfusion and therefore can differentiate between benign and malignant tumors. The most important routine clinical role of dynamic contrast-enhanced US is the prediction of tumor responses to chemotherapy within a very short time, shorter than using Response Evaluation Criteria in Solid Tumors criteria. Other applications found include quantifying the hepatic transit time, diabetic kidneys, transplant grafts, and Crohn disease. In addition, the problems involved in using dynamic contrast-enhanced US are discussed.

Ultrasound imaging in the diagnosis of benign and suspicious adrenal lesions

Background

The purpose of this study was to define the ultrasound imaging characteristics of adrenal tumors and to assess the performance of ultrasound in differentiating benign ‘leave-alone’ lesions from suspicious lesions.

Material/Methods

We enrolled 882 patients in this study. The nature of each lesion was determined by histopathology. Ultrasound finding of each lesion was compared with its corresponding histopathologic result. The final study group consisted of 911 adrenal masses in 882 patients. All images were reviewed by 2 experienced investigators in a double blind manner.

Results

There were 553 adenomas identified in the study, which constituted 60.70% of the lesions. There were 161 pheochromocytomas (17.67%), 49 myelolipomas (5.38%), 39 cysts (4.28%), 37 metastasis (4.06%), 35 ganglioneuromas (3.84%), 22 lymphomas (2.41%), and 15 cortical carcinomas (1.65%). The sensitivity, specificity, and accuracy of ultrasound-based diagnosis were 89%, 99%, and 93.9%, respectively. A positive predictive value of 90.9% and a negative predictive value of 94.2% were obtained in this study.

Conclusions

This large-sample study showed that ultrasound was a reliable method in differentiating benign ‘leave-alone’ lesions from suspicious lesions.

Contrast-enhanced ultrasound (CEUS) appearances of an adrenal phaeochromocytoma in a child with Von Hippel-Lindau disease

A phaeochromocytoma is a rare catecholamine-secreting tumour arising from the chromaffin cells. We describe a case of a child with Von Hippel-Lindau disease, with an adrenal phaeochromocytoma who presented with severe dilated cardiomyopathy driven by secondary hypertension. Contrast-enhanced ultrasound findings are described and compared with both magnetic resonance imaging and computed tomography imaging.

Adrenal oncocytic neoplasm: a systematic review

INTRODUCTION

Oncocytic neoplasms as tumors arising in the adrenal glands are rare, usually considered as nonfunctional and benign. In the current literature, there are extremely limited reports of adrenal oncocytic neoplasms; as to date, only 147 cases have been described. The rarity of the event prompted this study which reviews and presents the incidence, histology, diagnosis and therapy of adrenal oncocytic neoplasms.

MATERIALS AND METHODS

A review by systematic literature search was done using the MEDLINE®/Cochrane libraries from 1950 to date using the medical subject headings 'oncocytoma', 'adrenal gland', 'adrenal oncocytoma', 'adrenal oncocytic neoplasm' and 'adrenal oncocytic carcinoma'.

RESULTS

Adrenal oncocytic neoplasm is a rare disease, usually incidentally detected because only 17% are functional adrenal masses. The typical oncocyte displays abundant granular eosinophilic cytoplasm, due to the accumulation of mitochondria. Computed tomography and magnetic resonance imaging are not able to identify or differentiate benign and malignant oncocytic neoplasms. The mainstay of therapy is adrenalectomy, recently performed by laparoscopy. The prognosis is good for benign tumors, while adrenocortical oncocytic carcinoma has a poor survival rate of only 5 years.

CONCLUSIONS

Adrenal oncocytic neoplasm, a rare and mostly benign tumor, usually presents as an incidental, large adrenal mass; surgery is the mainstay of therapy, by means of laparoscopy which is now the most diffuse approach to adrenalectomy.

Contrast-enhanced endoscopic ultrasound

The European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) introduced guidelines on the use of contrast-enhanced ultrasound (CEUS) in 2004. This EFSUMB-document focused mainly on liver applications. However, new applications extending beyond the liver were developed thereafter. Increased interest in recent years in CEUS technique and in the application of CEUS in novel fields like endoscopic ultrasound (EUS) has revolutionized indications and applications. As a result, the EFSUMB initiated a new update of the guidelines in 2011 to include this additional knowledge. Some of the contrast-enhanced EUS (CE-EUS) indications are established, whereas others are preliminary; these latter indications are categorized as emergent CEUS applications since the available evidence is insufficient for general recommendation. This article focuses on the use of CE-EUS in various clinical settings. The reader will get an overview of current indications and possible applications of CE-EUS. This involves the introduction of different contrast studies including color Doppler techniques (known as contrast-enhanced high mechanical index endosonography or CEHMI-EUS) as well as more modern high-resolution contrast-enhanced techniques (known as contrast-enhanced low mechanical index endosonography or CELMI EUS).

Role of ultrasound and color Doppler imaging in the detection of carotid paragangliomas

INTRODUCTION

Carotid body paragangliomas (PGLs) are highly vascularized lesions that arise from the paraganglia located at the carotid bifurcation.

PURPOSE

To evaluate the usefulness of gray-scale ultrasound (US) and color Doppler ultrasound (CDUS) in the detection and follow-up of carotid PGLs of the neck.

MATERIALS AND METHODS

The authors retrospectively reviewed US and CDUS examinations of the neck performed in 40 patients with PGL syndrome type 1 and single or bilateral neck PGLs confirmed by CT or MRI; the patients had a total of 60 PGLs of the neck. US and CDUS outcome was compared to the outcome of second-line imaging techniques such as magnetic resonance imaging (MRI) or computed tomography (CT). The following findings were considered: presence/absence of focal lesions at US imaging and difference in maximum diameter of the lesion measured at US and MRI/CT. Results were compared using the Student's t-test.

RESULTS

Of the 60 PGLs of the neck only 5 (8.3%) were not visualized at US or CDUS examination. The difference in maximum diameter of these lesions measured at CT/MRI and US/CDUS ranged between -5 mm and +16 mm (mean difference 2.2 ± 6.0). This difference was statistically significant (p = 0.008).

CONCLUSIONS

US and CDUS are useful methods for identifying carotid PGLs also measuring less than 10 mm in diameter. However, diagnostic accuracy of US and CDUS is reduced in the measurement of the exact dimensions of the lesions.