Ultrasound imaging in the diagnosis of benign and suspicious adrenal lesions

Imaging of pregnant and lactating patients with suspected adrenal disorders

A high level of clinical suspicion is essential in the diagnosis and management of a suspected adrenal mass during pregnancy and the peripartum period. Timely recognition is important in order to improve fetal and maternal outcomes. Imaging is often performed to confirm a suspected adrenal lesion; however, increasing usage of diagnostic imaging during pregnancy and lactation has also increased awareness, concerns and confusion regarding the safety risks regarding fetal and maternal exposure to radiation and imaging intravenous contrast agents. This may lead to anxiety and avoidance of imaging examinations which can delay diagnosis and appropriate treatment. This article briefly reviews evidence-based recommended imaging modalities during pregnancy and the lactation period for the assessment of a suspected adrenal mass while recognizing that no examination should be withheld when the exam is necessary to confirm an important clinical suspicion. The imaging characteristics of the more common adrenal pathologies that may affect pregnant women are also discussed.

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.

Draft of the clinical practice guidelines “Adrenal incidentaloma”

The wider application and technical improvement of abdominal imaging procedures in recent years has led to an increasingly frequent detection of adrenal gland masses — adrenal incidentaloma, which have become a common clinical problem and need to be investigated for evidence of hormonal hypersecretion and/or malignancy. Clinical guidelines are the main working tool of a practicing physician. Laconic, structured information about a specific nosology, methods of its diagnosis and treatment, based on the principles of evidence-based medicine, make it possible to give answers to questions in a short time, to achieve maximum efficiency and personalization of treatment. These clinical guidelines include data on the prevalence, etiology, radiological features and assessment of hormonal status of adrenal incidentalomas. In addition, this clinical practice guideline provides information on indications for surgery, postoperative rehabilitation and follow-up.

[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.

Coincidence of Large Adrenal Cyst and Prominent Hyporeninemic Hyperaldosteronism

A 67-year-old Japanese woman who had end-stage renal disease was referred to our hospital for kidney transplantation. Abdominal CT revealed a large adrenal mass with inhomogeneity. She had a history of hospitalization for stroke and heart failure and exhibited prominent hyporeninemic hyperaldosteronism. Histological examination of the resected tumor with anti-CYP11B2 antibody indicated that she had a vascular endothelial cyst with primary aldosteronism (PA) due to multiple adrenocortical micronodules. This report implicates the pathological interaction between adrenal vascular cysts and PA-mediated vascular damage of the adrenal vein.

Ultrasonographic Findings of 1385 Adrenal Masses: A Retrospective Study of 1319 Benign and 66 Malignant Masses

OBJECTIVES

To evaluate the features of adrenal masses on ultrasonography and correlate the findings with the pathologic diagnoses to help distinguish benign from malignant adrenal lesions.

METHODS

Ultrasonography was performed in 1363 patients with adrenal lesions. The following ultrasonographic parameters were recorded: size, shape, margin, echogenicity, echo texture, cystic necrosis, calcifications, and blood supply. The sensitivity and specificity of aggressive features for predicting malignancy were calculated.

RESULTS

Of 1385 adrenal lesions, 66 (4.8%) were malignant: 33 malignant pheochromocytomas, 20 adrenal cortical carcinomas, 10 metastases, 2 leiomyosarcomas, and 1 primitive neuroectodermal tumor. The remaining 1319 (95.2%) lesions were benign: 832 adenomas, 182 pheochromocytomas, 153 nodular adrenal hyperplasia, 54 myelolipomas, 42 cysts, 23 ganglioneuromas, 10 schwannomas, 8 cortical tumor eosinophils, 4 teratomas, 4 tuberculosis, 4 primary pigmented nodular adrenocortical disease, and 3 Castleman disease. Most of the tumors were regular and hypoechoic. The malignant lesions were significantly larger than the benign lesions (mean ± SD, 6.3 ± 2.4 versus 4.6 ± 1.7 cm; P < .01). Significant differences between malignant and benign tumors were observed when comparing the shape, margins, echo texture and vascularization of the analyzed lesions (P < .01). An irregular shape, poor definition of margins, heterogeneous echo texture, and vascularization indicated malignancy, with sensitivity and specificity of 45.5% and 97.0%, 34.8% and 99.2%, 92.4% and 97.3%, and 15.2% and 97.5%, respectively.

CONCLUSIONS

Ultrasonography could be an effective diagnostic supplementary tool for adrenal tumors. A large size, irregular shape, poorly defined margins, heterogeneous echo texture, and vascularization of adrenal lesions could be effective indicators of malignancy.

Point of care ultrasound in thoracic malignancy

Ultrasonography is a safe, efficient and cost-effective mode of imaging that can assist clinicians with important treatment decisions and provide procedural guidance. Today, point of care ultrasound plays an essential role in the assessment of benign and malignant conditions of chest, both in the outpatient and inpatient setting. Small, ultra-portable, affordable units can now be carried in the coat pocket. Advanced lung cancer, metastatic diseases to the lungs or thoracic malignancies can present with pleural effusion, pulmonary edema, post-obstructive pneumonia, or ascites that can be assessed by the clinician with ultrasound. It can be used to evaluate the extent of thoracic tumors beyond the parenchyma to the parietal pleura or chest wall, assess cervical, supraclavicular lymphadenopathy prior to fine needle aspiration or to determine venous thromboembolism (VTE) associated with malignancy. Thoracic ultrasound is currently being practiced by the pulmonologists, thoracic surgeons and intensivists to provide guidance during placement of pleural catheters, chest tubes or to evaluate the pleural cavity before thoracoscopy. Point of care ultrasound can improve efficiency in procedures by decreasing complications, increasing success and reducing financial strain on the health care system.

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.

A case of epithelial adrenal gland cyst

Introduction: Adrenal gland cysts are relatively rare cystic lesions, which are usually discovered incidentally with the widespread use of radiological imaging techniques. Case report: We reported a clinical case of a 36-year -old woman who presented with a 6 months history of right flank discomfort. The contrast-enhanced abdominal computed tomography revealed a well-circumscribed cystic lesion with a capsule in the Morrison's pouch measuring 57 x 51 mm. On abdominal magnetic resonance imagining (MRI), the cystic lesion exhibited a hypointensity on T-1 weighted images and hyperintensity on T-2 weighted images. Surgery was decided because of lesion size and doubts concerning its etiology. The final histopathological diagnosis was an epithelial cyst of the adrenal gland. In summary, epithelial adrenal cysts are uncommon retroperitoneal lesions. In our case, open adrenalectomy was performed and the prognosis was excellent.

Ultrasonographic features of adrenal gland lesions in dogs can aid in diagnosis

BACKGROUND

Ultrasonography to visualize adrenal gland lesions and evaluate incidentally discovered adrenal masses in dogs has become more reliable with advances in imaging techniques. However, correlations between sonographic and histopathological changes have been elusive. The goal of our study was to investigate which ultrasound features of adrenal gland abnormalities could aid in discriminating between benign and malignant lesions. To this end, we compared diagnosis based on ultrasound appearance and histological findings and evaluated ultrasound criteria for predicting malignancy.

RESULTS

Clinical records of 119 dogs that had undergone ultrasound adrenal gland and histological examination were reviewed. Of these, 50 dogs had normal adrenal glands whereas 69 showed pathological ones. Lesions based on histology were classified as cortical adrenal hyperplasia (n = 67), adenocarcinoma (n = 17), pheochromocytoma (n = 10), metastases (n = 7), adrenal adenoma (n = 4), and adrenalitis (n = 4). Ultrasonographic examination showed high specificity (100%) but low sensitivity (63.7%) for identifying the adrenal lesions, which improved with increasing lesion size. Analysis of ultrasonographic predictive parameters showed a significant association between lesion size and malignant tumors. All adrenal gland lesions >20 mm in diameter were histologically confirmed as malignant neoplasms (pheochromocytoma and adenocarcinoma). Vascular invasion was a specific but not sensitive predictor of malignancy. As nodular shape was associated with benign lesions and irregular enlargement with malignant ones, this parameter could be used as diagnostic tool. Bilaterality of adrenal lesions was a useful ultrasonographic criterion for predicting benign lesions, as cortical hyperplasia.

CONCLUSIONS

Abnormal appearance of structural features on ultrasound images (e.g., adrenal gland lesion size, shape, laterality, and echotexture) may aid in diagnosis, but these features alone were not pathognomic. Lesion size was the most direct ultrasound predictive criterion. Large and irregular masses seemed to be better predictors of malignant neoplasia and lesions <20 mm in diameter and nodular in shape were often identified as cortical hyperplastic nodules or adenomas.

Echogenicity of benign adrenal focal lesions on imaging with new ultrasound techniques - report with pictorial presentation

Aim

The aim of the research was to assess the echogenicity of benign adrenal focal lesions using new ultrasound techniques.

Material and method

34 benign adrenal masses in 29 patients were analyzed retrospectively. The examinations were conducted using Aplio XG (Toshiba, Japan) ultrasound scanner with a convex probe 1–6 MHz in the B-mode presentation with the combined use of new ultrasound techniques: harmonic imaging and spatial compound sonography. The size of the adrenal tumors, their echogenicity and homogeneity were analyzed. Statistical analysis was conducted using the STATISTICA 10 software.

Results

The following adrenal masses were assessed: 12 adenomas, 10 nodular hyperplasias of adrenal cortex, 7 myelolipomas, 3 pheochromocytomas, a hemangioma with hemorrhage and a cyst. The mean diameter of nodular hyperplasia of adrenal cortex was not statistically different from that of adenomas (p = 0.075). The possibility of differentiating between nodular hyperplasia and adenoma using the parameter of hypoechogenicity or homogeneity of the lesion was demonstrated with the sensitivity and specificity of 100% and 41.7%, respectively. The larger the benign adrenal tumor was, the more frequently did it turn out to have a mixed and inhomogenous echogenicity (p < 0.05; ROC areas under the curve: 0.832 and 0.805, respectively).

Conclusions

A variety of echogenicity patterns of benign adrenal focal lesions was demonstrated. The image of an adrenal tumor correlates with its size. The ultrasound examination, apart from its indisputable usefulness in detecting and monitoring adrenal tumors, may also allow for the differentiation between benign lesions. However, for lesions found incidentally an algorithm for the assessment of adrenal incidentalomas is applicable, which includes computed tomography and magnetic resonance imaging.