Magnetic resonance imaging of adrenal gland: state of the art

Current perspectives on the diversification of endoscopic ultrasound-guided fine-needle aspiration and biopsy

Endoscopic ultrasound-guided tissue acquisition (EUS-TA) has undergone significant advancements since it was first reported in 1992. Initially focused on the pancreas, EUS-guided fine-needle aspiration (FNA) has now been extended to encompass all organs proximal to the gastrointestinal system. Recently, a novel fine-needle biopsy (FNB) needle with an end-cut tip was developed, allowing for the collection of specimens suitable for histological assessment, a feat hard to achieve with traditional needles. The FNB needle holds promise for applications in immunohistochemistry staining and genetics evaluation, and it has the potential to yield specimens of comparable quality to core needle biopsy during percutaneous puncture, especially for lesions beyond the pancreas, such as lymph nodes. This review focuses on the efficacy of EUS-FNA/FNB for extended target regions, specifically lymph nodes, spleen, adrenal gland, and ascites. The indications for EUS-FNA have greatly expanded beyond the pancreas over the years, and future improvements and innovations in puncture needles will allow for the collection of higher-quality specimens, which is expected to play a significant part in personalized cancer treatment.

Coexistence of Bilateral Giant Adrenal Myelolipomas and Congenital Adrenal Hyperplasia: A Case Report

Adrenal myelolipomas (AMs) are rare and benign neoplasms, consisting of adipose and mature hematopoietic tissue. They are commonly discovered incidentally with increased use of radiologic imaging. A small number of giant bilateral adrenal masses are reported, particularly in the setting of congenital adrenal hyperplasia (CAH). We report the case of a 36-year-old male with a history of CAH on steroids since childhood, self-discontinued shortly after diagnosis, presenting mainly with abdominal distension and pain besides infertility. Imaging revealed giant bilateral adrenal masses. Subsequently, he underwent bilateral adrenalectomy, and the surgical pathology report revealed myelolipomas measuring 39×17×8 cm on the left and weighing 4050 grams and 28×16×5 cm on the right and weighing 1702 grams. AMs are found to coexist with many other conditions such as Cushing's syndrome, pheochromocytoma, and CAH. We discuss the association with high adrenocorticotropic hormone (ACTH) states and review the studies involving ACTH as a stimulator leading to myelolipomas. This case report highlights the proper history taking and biochemical evaluation for early detection and intervention to avoid catastrophic consequences.

Simplified urinary steroid profiling by LC-MS as diagnostic tool for malignancy in adrenocortical tumors

OBJECTIVES

Preoperative identification of malignant adrenal tumors is challenging. 24-h urinary steroid profiling by LC-MS/MS and machine learning has demonstrated high diagnostic power, but the unavailability of bioinformatic models for public use has limited its routine application. We here aimed to increase usability with a novel classification model for the differentiation of adrenocortical adenoma(ACA) and adrenocortical carcinoma(ACC).

METHODS

Eleven steroids (5-pregnenetriol, dehydroepiandrosterone, cortisone, cortisol, α-cortolone, tetrahydro-11-deoxycortisol, etiocholanolone, pregnenolone, pregnanetriol, pregnanediol, and 5-pregnenediol) were quantified by LC-MS/MS in 24-h urine samples from 352 patients with adrenal tumor (281 ACA,71 ACC). Random forest modelling and decision tree algorithms were applied in training (n=188) and test sets (n=80) and independently validated in 84 patients with paired 24-h and spot urine.

RESULTS

After examining different models, a decision tree using excretions of only 5-pregnenetriol and tetrahydro-11-deoxycortisol classified three groups with low, intermediate, and high risk for malignancy. 148/217 ACA were classified as being at low, 67 intermediate, and 2 high risk of malignancy. Conversely, none of the ACC demonstrated a low-risk profile leading to a negative predictive value of 100% for malignancy. In the independent validation cohort, the negative predictive value was again 100% in both 24-h urine and spot urine with a positive predictive value of 87.5% and 86.7%, respectively.

CONCLUSIONS

This simplified LC-MS/MS-based classification model using 24-h-urine provided excellent results for exclusion of ACC and can help to avoid unnecessary surgeries. Analysis of spot urine led to similarly satisfactory results suggesting that cumbersome 24-h urine collection might be dispensable after future validation.

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.

Adrenal myelolipoma: Defining the role of surgery. A case report

Introduction and importance

Adrenal myelolipomas (AMLs) are rare, non-functional, benign tumours mostly diagnosed incidentally. They present as small and unilateral masses that are histologically composed of mature adipose tissue with admixed haemopoietic elements. In a small percentage of patients, pressure symptoms, retroperitoneal haemorrhage or tumour rupture may occur. However, indications for surgery in the majority of asymptomatic patients are poorly defined.

Case presentation

A 44-year old male patient presented with signs of gastroenteritis. Computed tomography (CT) imaging revealed an encapsulated, sharply delineated mass measuring 87 × 76 × 87 mm displacing the right adrenal gland. Average attenuation was −30 Hounsfield units. Given the pathognomonic features, an AML was suspected. The patient underwent open tumour resection and the diagnosis was histologically confirmed.

Clinical discussion

Small (<4 cm), homogeneous, non-hormone secreting incidentalomas with an attenuation of <10 Hounsfield units on non-contrast CT are considered benign requiring neither treatment nor follow-up. Giant AMLs (>10 cm) may cause symptoms or complications and are therefore considered candidates for surgery. The treatment strategy of asymptomatic AMLs ranging from 4 cm to 10 cm, however, is controversial and poorly defined. The role of surgery in this specific subgroup of patients is studied.

Conclusion

Surgery is indicated in the presence of a tumour diameter above 6 cm, rapid tumour growth (RECIST 1.1 criteria for progressive disease at 6–12 months follow-up), imaging suspicious of malignancy, radiological signs of local invasion, functioning ipsilateral adrenocortical adenoma, pressure-related symptoms and signs of retroperitoneal bleeding or spontaneous tumour rupture.

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Adrenal myelolipoma are rare, non-functional, usually small, benign tumours.

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They are composed of mature adipose tissue and haemopoietic elements.

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95 % of adrenal myelolipomas are asymptomatic and discovered as incidentalomas.

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The role of surgery in the treatment of mid-sized lesions (4–6 cm) is poorly defined.

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The present study states the indications for surgery of mid-sized lesions (4–6 cm).

Clinical presentation, management, and research progress of adrenal schwannoma

Objective

This study shares our experience in managing adrenal schwannoma (AS).

Methods

The clinical data of eight patients with AS in our hospital from April 2007 to April 2022 were analyzed retrospectively.

Results

A total of 1309 patients with adrenal lesions were treated in the affiliated hospital of Guizhou Medical University for 15 years, of which only 8 cases were diagnosed as AS, accounting for 0.61%. Among the eight patients with AS, there were five females and three males, with an average age of 48.63 ± 12.05 years, and the average maximum diameter of the tumor was 6.96 ± 1.83 cm. All patients underwent adrenalectomy and were pathologically diagnosed as AS after the operation. The average follow-up time of eight patients with AS was 60.13 ± 22.33 months, and there was no recurrence or metastasis.

Conclusion

The retroperitoneum is an uncommon site for schwannoma tumors, and among adrenal incidentalomas, the schwannoma is rare. The disease lacks specific clinical and imaging features, but correct diagnosis before the pathological examination is very important for clinical management and surgical decision. When imaging examination indicates a slow-growing retroperitoneal mass, schwannoma should be considered. Surgical resection is the main treatment. Pathology is the gold standard for diagnosis. Most of the tumors are benign and have a good prognosis. There is a risk of recurrence after the operation, and it should be monitored actively.

Rare Primary Adrenal Tumor: A Case Report of Teratomas and Literatures Review

Teratomas are very rare, originating from embryonal germ layers. The majority of them are mature, most common in the gonads, and with only 15% out of gonads. In particular, primary adrenal teratomas are extremely rare. The present study reported a case of a young female patient with right adrenal tumor who underwent intermittent pain in the right waist and abdomen and whose CT of adrenal gland showed an 88 mm × 79 mm × 69 mm mass. Besides, her adrenal gland-related hormones are not abnormal. Laparoscopic adrenal tumor resection was performed on her and the histopathological results confirmed that the mass was mature adrenal teratomas. As a newly diagnosed case, strict and regular follow-up is needed, and it is also necessary to detect her AFP and check her adrenal CT in the future. In addition, we have reviewed the literature from 1952 to the present, and a total of 49 cases of adrenal teratoma have been identified and analyzed.

Factors predicting prolonged glucocorticoid therapy in patients with adrenal insufficiency after laparoscopic adrenalectomy. Case report

Introduction and importance

Adrenal insufficiency (AI) is common after adrenalectomy for Primary Adrenal Cushing's syndrome (PACS), due to the inhibition of the Hypothalamic-Pituitary-Adrenal Axis (HPAA) by the functioning adrenal mass. The treatment of post-surgical AI is based mainly on glucocorticoid supplementation therapy. To date, however, there is no known predicting factor of the duration of supplementation therapy in patients treated with laparoscopic adrenalectomy for PACS.

Case presentation

We report the case of a 22-year-old Caucasian female who presented with dyspnea, osteoporosis, vertebral collapses and fractures of the pelvis. The diagnosis of ACTH-independent Cushing's syndrome was provided. Abdominal MRI revealed a left adrenal mass suggestive for adrenal adenoma, highly suggestive for PACS. The patient underwent left laparoscopic adrenalectomy. After surgery, glucorticoid supplementation therapy was started. More than A-year steroid replacement therapy was necessary before the patient completely recovered the function of the HPAA. During this period the patient was strictly followed up in order to adjust pharmacologic treatment, thus allowing to investigate the possible causes of such a slow and hard recover of the contralateral adrenal gland function.

Conclusion

AI is common after adrenalectomy for PACS due to HPAA suppression. The duration of steroid replacement therapy may be vary depending on patient's characteristics and may be uncommonly long, as in our case. We concluded the not only cortisol and ACTH level, but also radiological findings, such as the size of the mass, its functional activity as well as the hypotrophy or atrophy of the contralateral adrenal gland may be predictive of the duration of the steroid therapy. These factors, if correctly studied before surgery, may be of help in tailoring the postoperative management of the patients after adrenalectomy.

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Adrenal insufficiency is common after adrenalectomy for secreting masses.

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In some cases long-lasting glucocorticoid replacement therapy is required before regular function of the contralateral adrenal gland is restored.

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The high level of cortisol may lead to strong suppression of the Hypothalamic-Pituitary-Adrenal Axis (HPAA), that in turn may lead to hypotrophy of the contralateral adrenal gland.

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No predictive factor of the need for prolonged steroid therapy has been reported in the literature to date. However, some radiological findings, such as the width of the contralateral adrenal gland is associated to the need of a prolonged glucocorticoid replacement therapy in the post-operative time.

Differentiation between heterogeneous adrenal adenoma and non-adenoma adrenal lesion with CT and MRI

PURPOSE

To assess whether heterogeneous adrenal adenomas can be distinguished from heterogeneous non-adenomas with Computed Tomography (CT) and/or Magnetic Resonance Imaging (MRI).

METHOD

From 2009 to 2019, 980 consecutive adrenalectomies were retrospectively identified. Patients without adequate CT/MRI, with homogeneous and/or < 1 cm lesions were excluded. Differences between adenomas and non-adenomas were analyzed using Chi-square, Student t or Fischer tests, and interobserver agreement using weighted kappa test or intraclass correlation coefficient. Independent variables associated with adenomas were searched for using multivariable analysis. Area under the receiver operating characteristic curve (AUC) of the final model and its diagnostic performances were calculated.

RESULTS

Final population comprised 183 patients (106 women, 77 men, mean age 53.2 ± 14.4 years) with 124 non-adenomas and 59 heterogeneous adenomas. Macroscopic or microscopic fat on CT/MRI allowed diagnosis of adenoma with 98% specificity and 63% sensitivity. Interobserver agreement was almost perfect for macroscopic fat (k = 0.82; 95% CI 0.66; 0.94) and substantial for microscopic fat (k = 0.75; 95% CI 0.62; 0.86). A multivariable model including micro- or macroscopic fat [Odds ratio (OR) 81.19; 95% CI 20.17; 572.27], diameter < 5.5 cm (OR 7.32; 95% CI 2.17; 31.28), calcifications (OR 5.68; 95% CI 2.08; 16.18), and hemorrhage (OR 3.10; 95% CI 0.70; 15.35) had an AUC of 0.91 (95% CI 0.86; 0.96), 71% (42/59, 95% CI 58; 82) sensitivity, 93% (115/124; 95% CI 87; 97) specificity, and 86% (157/183; 95% CI 79; 90) accuracy for the diagnosis of adenoma.

CONCLUSION

A multivariable model enables CT/MR diagnosis of heterogeneous adenomas. Presence of microscopic fat, even if partial, in a heterogeneous mass is highly specific of adenoma.

Endocrine Toxicities of Antineoplastic Therapy: The Adrenal Topic

Simple Summary

Primary adrenal insufficiency (PAI) induced by anticancer drugs is a rare occurrence. However, with the expanding use of immune checkpoint inhibitors (ICIs), an increasing number of patients affected by ICI-induced PAI are expected. As a result, oncologists should be aware of the risk of PAI in patients on ICIs (and other anticancer agents) and the related clinical presentations to diagnose this condition early, provide the appropriate treatment, and timely involve endocrinologists in the management of those patients. In parallel, patients on these medications, together with their caregivers and relatives, should receive detailed information about PAI risk and be trained to act appropriately at the onset of alarm symptoms. Large collaborative trials are needed to develop appropriate tests to assess the personal risk of drug induced PAI better and improve its early diagnosis in cancer patients and patients affected by other forms of PAI.

Abstract

Immune checkpoint inhibitors (ICIs) have improved survival in patients affected by several solid tumours at the cost of new autoimmune adverse events. Endocrine toxicity is frequently reported in patients treated with these agents, mainly as thyroid dysfunction and hypophysitis. Primary adrenal insufficiency is reported in 1–2% of patients receiving a single ICI, but its rate is approximately 5% in patients treated with a combination of two ICIs. The clinical presentation of adrenal insufficiency may be insidious due to symptoms that are not specific. The same symptoms in cancer patients are frequently multifactorial, rendering the early diagnosis of adrenal insufficiency challenging in this group of patients. As adrenal insufficiency can be fatal if not rapidly diagnosed and treated, oncologists should be aware of its clinical presentations to timely involve endocrinologists to offer patients the appropriate management. In parallel, it is essential to educate patients, their caregivers, and relatives, providing them with detailed information about the risk of adrenal insufficiency and how to manage alarming symptoms at their onset. Finally, large collaborative trials are needed to develop appropriate tests to assess better the personal risk of drug-induced adrenal insufficiency and its early diagnosis and treatment, not only in cancer patients.

3.0-Tesla MRI of normal canine adrenal glands

Adrenal disease is a common problem in dogs and MRI is increasingly being used as an adjunctive diagnostic test. To date, the MRI features of normal canine adrenal glands have only been reported using 1.5-Tesla (T) MRI. The aims of this prospective, methods-comparison, exploratory study were to evaluate the effects of pulse sequence on the appearance of normal canine adrenal glands using 3 Tesla MRI. Six research beagle dogs were sampled and the following pulse sequences were acquired for each: (1) T2-weighted images using two-dimensional (2D) turbo spin-echo (TSE), single-shot spin-echo (SSTSE), and three-dimensional (3D) TSE, (2) T1-weighted images using 2D TSE, 3D TSE, and 3D turbo field echo sequences, (3) post-contrast T1-weighted images, and (4) chemical shift imaging. The signal-to-noise ratio and contrast-to-noise ratio were measured for each dog and each pulse sequence. The signal intensity, clarity of the contour, distinction of the corticomedullary junction, degrees of motion, partial volume, and chemical shift artifact, and homogeneity of the contrast enhancement were evaluated qualitatively. In all sequences, except for chemical shift imaging, the adrenal glands were visualized in both planes with successful control of motion artifacts by manual ventilation. The adrenal contour was considered to be most clearly visualized with 2D TSE. Adrenal images were acquired within the shortest time using SSTSE although the contour was less clearly visualized than with TSE. Findings from this study in normal dogs can serve as background for further 3.0-T MRI studies of dogs with adrenal disease.

Percutaneous Radiofrequency Ablation (RFA) in renal cancer. How to manage challenging masses. A narrative review

In the last decades, the refinements in the imaging techniques led to an increased number of detected renal tumors. If radical and partial nephrectomy remain the gold standard for the treatment of renal cancer, Radio-Frequency Ablation (RFA) has emerged as a therapeutic option for renal masses. Even if this technique is minimally-invasive, it requires a proper preoperative anatomic study and in some cases RFA treatment is technically challenging. To date, there is no standardization for studying challenging cases before treatment and to plan a safe and effective procedure when intervening organs are in the trajectory of the needle. In this study we searched the literature focusing on the challenging cases and strategy applied to manage the treatment safely and effectively.

MATERIALS AND METHODS

MedLine and Embase via Ovid database were searched, using the following key words: Percutaneous RFA, radiofrequency, renal ablation, kidney ablation, renal thermoablation, kidney thermoablation, hydrodissection, heat sink. The difficulties found in the literature while performing the ablation procedure were grouped and a categorization of the strategies applied to perform a safe and effective procedure was proposed, in the aim to standardize the approach for treatment of challenging cases. Literature was analyzed according with selection criteria agreed by the Authors.

RESULTS

The literature review showed four groups of lesions requiring an experienced approach. Group 1: Lesions close to the bowel. Group 2: Lesions close to the urinary tract. Group 3: Lesions close to intervening organs. Group 4: Lesions close to large vessels (heat-sink phenomenon).

CONCLUSION

When planning a RFA treatment, a standardized approach to challenging masses is possible. This review make the treatment of these masses more systematic and safe.

Computed Tomography-Based Machine Learning Differentiates Adrenal Pheochromocytoma From Lipid-Poor Adenoma

OBJECTIVES

To assess the accuracy of computed tomography (CT)-based machine learning models for differentiating subclinical pheochromocytoma (sPHEO) from lipid-poor adenoma (LPA) in patients with adrenal incidentalomas.

PATIENTS AND METHODS

The study included 188 tumors in the 183 patients with LPA and 92 tumors in 86 patients with sPHEO. Pre-enhanced CT imaging features of the tumors were evaluated. Machine learning prediction models and scoring systems for differentiating sPHEO from LPA were built using logistic regression (LR), support vector machine (SVM) and random forest (RF) approaches.

RESULTS

The LR model performed better than other models. The LR model (M1) including three CT features: CT_pre value, shape, and necrosis/cystic changes had an area under the receiver operating characteristic curve (AUC) of 0.917 and an accuracy of 0.864. The LR model (M2) including three CT features: CT_pre value, shape and homogeneity had an AUC of 0.888 and an accuracy of 0.832. The S2 scoring system (sensitivity: 0.859, specificity: 0.824) had comparable diagnostic value to S1 (sensitivity: 0.815; specificity: 0.910).

CONCLUSIONS

Our results indicated the potential of using a non-invasive imaging method such as CT-based machine learning models and scoring systems for predicting histology of adrenal incidentalomas. This approach may assist the diagnosis and personalized care of patients with adrenal tumors.

Primary adrenal tuberculosis infection in patients with Behcet's disease presenting as isolated adrenal metastasis by 18F-FDG PET/CT: a rare case report and literature review

Primary adrenal tuberculosis (TB) is a rare type of extrapulmonary tuberculosis (EPTB). A pathological biopsy is usually required to make a definite diagnosis due to nonspecific symptoms. Antituberculous chemotherapy is the main treatment regimen, and cortisol replacement therapy should be added when adrenal insufficiency is involved. Here, we present a 59-year-old man who had recurrence of oral and genital aphthosis for 3 years and was diagnosed with Behcet's disease (BD), which was cured by thalidomide. After 10 days of admission, the patient had sudden abdominal pain in the right upper quadrant with high fever and was diagnosed with acute cholecystitis attack, which was treated by percutaneous transhepatic gallbladder drainage (PTGBD). Further contrast-enhanced CT showed a right adrenal mass with a diameter of 2.0 cm, and PET-CT indicated intense ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) uptake in the right adrenal mass with a maximum standardized uptake value (SUV_max) of 15.2. As a metastatic adrenal mass was suspected, the patient underwent retroperitoneal laparoscopic adrenalectomy. Histopathological and immunohistochemical analysis revealed primary adrenal TB. After routine anti-tuberculosis treatment with isoniazid, rifampin, pyrazinamide and ethambutol for six months, the patient was cured and discharged. In summary, primary unilateral adrenal TB without adrenal insufficiency is difficult to diagnose only on the basis of clinical manifestations and examinations. Further studies are needed to develop an easier and more accurate diagnostic examination.

Adrenal myelolipomas

Adrenal myelolipomas are benign, lipomatous tumours with elements of myeloid cells, most of which present as adrenal incidentalomas and comprise 3·3-6·5% of all adrenal masses. Adrenal myelolipomas are usually unilateral (in 95% of cases), variable in size, most often found during midlife, and affect both sexes almost equally. On imaging, adrenal myelolipomas show pathognomonic imaging features consistent with the presence of macroscopic fat. Large adrenal myelolipomas can cause symptoms of mass effect, and can occasionally be complicated by haemorrhage. In the event of a concomitant adrenal cortical adenoma or hyperplasia, adrenal hormone excess might be detected in patients with adrenal myelolipoma. Patients with congenital adrenal hyperplasia exhibit a higher prevalence of adrenal myelolipomas than other patient groups, and are at risk of developing large and bilateral lesions. This Review discusses the pathogenesis, clinical presentation, and management of adrenal myelolipomas.

Stereotactic body radiation therapy (SBRT) for patients with oligometastatic/oligoprogressive adrenal metastases: Outcomes and toxicities profile in a monoinstitutional study

AIMS

To evaluate survival outcomes and toxicology profiles in oligometastatic/oligoprogressive patients treated with SBRT for adrenal metastases.

METHODS

We retrospectively analyzed 25 metastatic adrenal lesions in 24 oligometastatic/oligoprogressive patients undergoing ablative Stereotactic Body Radiation Therapy (SBRT) between February 2010 and November 2019 in our department. The primary endpoint was overall survival (OS). Secondary endpoints were local overall response rate (ORR), acute and late toxicities.

RESULTS

The most common primary tumor was non-small cell lung cancer (54%). Twenty-one patients received chemo or immuno-therapy. The median planning target volume (PTV) was 41.7 cm³. Median SBRT dose was 36 Gy. Median dose per fraction was 15 Gy. Median survival was 35-months with OS outcomes ranging from 6-months (100%), 1-year (87.5%) and 2-years (66.7%). ORR based on RECIST criteria was 66.5%. 12 patients experienced acute toxicities, mostly grade 1-2 (8 patients, 32%).

CONCLUSIONS

SBRT for oligometastatic/oligoprogressive patients with adrenal metastases showed acceptable survival outcomes and a safe toxicity profile.

Adult adrenal neuroblastoma: A case report

Adrenal neuroblastoma (NB) is very rare in adults. According to the literature, <100 cases have been reported worldwide to date, with >90% of the patients aged <10 years. As the early symptoms of the disease are not obvious, distant metastasis has often already occurred when the patients develop clinical symptoms. This lack of obvious symptoms may lead to misdiagnosis and inadequate treatment. Imaging and laboratory examinations are crucial for the diagnosis of NB, but reaching a definitive diagnosis prior to surgery is challenging, as the final diagnosis ultimately depends on histopathological examination. The aim of the present study was to report the rare case of a 40-year-old woman with adrenal left NB who underwent tumor resection. No tumor recurrence was observed at the 3-month and 1-year postoperative follow-up, but a repeat computed tomography at the 3-year postoperative follow-up indicated metastases; the patient refused further treatment and eventually succumbed to the disease within 1 month. The aim of the present case was to emphasize the importance of individualized therapy and long-term, close follow-up of the patients. The clinical characteristics and treatment of this case of adrenal NB were also summarized and analyzed in order to raise clinical awareness of this rare disease.

[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.

Handcrafted MRI radiomics and machine learning: Classification of indeterminate solid adrenal lesions

PURPOSE

To assess a radiomic machine learning (ML) model in classifying solid adrenal lesions (ALs) without fat signal drop on chemical shift (CS) as benign or malignant.

METHOD

55 indeterminate ALs (21 lipid poor adenomas, 15 benign pheocromocytomas, 1 oncocytoma, 12 metastases, 6 primary tumors) showing no fat signal drop on CS were retrospectively included. Manual 3D segmentation on T2-weighted and CS images was performed for subsequent radiomic feature extraction. After feature stability testing and an 80-20% train-test split, the train set was balanced via oversampling. Following a multi-step feature selection, an Extra Trees model was tuned with 5-fold stratified cross-validation in the train set and then tested on the hold-out test set.

RESULTS

A total of 3396 features were extracted from each AL, of which 133 resulted unstable while none had low variance (< 0.01). Highly correlated (r > 0.8) features were also excluded, leaving 440 parameters. Among these, Support Vector Machine 5-fold stratified cross-validated recursive feature elimination selected a subset of 6 features. ML obtained a cross-validation accuracy of 0.94 on the train and 0.91 on the test sets. Precision, recall and F1 score were respectively 0.92, 0.91 and 0.91.

CONCLUSIONS

Our MRI handcrafted radiomics and ML pipeline proved useful to characterize benign and malignant solid indeterminate adrenal lesions.

Diffusion Weighted Imaging in Unilateral Adrenal Infarction: A Case of Colicky Right Upper Quadrant Pain in a Pregnant Female

Diffusion weighted imaging (DWI) is a magnetic resonance imaging (MRI) non-contrast sequence that can indicate tissue ischemia or infarction. Adrenal infarct may present similarly to biliary or gallbladder pathologies, and the differential diagnosis during emergency work-up can be narrowed utilizing DWI sequences. In this paper, we describe the usefulness of DWI for urgent diagnosis in a case of non-hemorrhagic adrenal infarct of a pregnant female presenting with right upper quadrant pain. Although uncommon, adrenal infarct may occur in patients with hypercoagulability and localizing pain that is unexplained by other imaging modalities. We outline the imaging features of DWI in evaluating adrenal infarct as a safe and time effective application for patients with contraindications to imaging with ionizing radiation.

Pitfalls and differential diagnosis on adrenal lesions: current concepts in CT/MR imaging: a narrative review

The purpose of this pictorial essay is to review the imaging findings of adrenal lesions. Adrenal lesions could be divided into functioning or non-functioning masses, primary or metastatic, and benign or malignant. Imaging techniques have undergone significant advances in recent years. The most significant objective of adrenal imaging is represented by the detection and, when possible, characterization of adrenal lesions in order to direct patient management correctly. The detection and management of adrenal lesions is based on cross-sectional imaging obtained with non-contrast CT (tumour density), contrast-enhanced CT including delayed washout (either absolute percentage washout or relative percentage one) and finally with MR chemical shift analysis (loss of signal intensity between in-phase and out-of-phase images including both qualitative and quantitative estimates of signal loss). The small incidental adrenal nodules are benign, in most of cases; some tumors such as lipid-rich adenoma and myelolipoma have characteristic features that can be diagnosed accurately in CT. On contrary, if the presenting contrast-enhanced CT shows an adrenal mass with uncertain or malignant morphologic features, particularly in patients with a known history of malignancy, further evaluations should be considered. The most significative implications for radiologists are represented by how to assess risk of malignancy on imaging and what follow-up to indicate if an adrenal incidentaloma is not surgically removed.

PSA-IgM and iXip in the diagnosis and management of prostate cancer: clinical relevance and future potential. A review

The Prostate Specific Antigen (PSA) is the first filter in the diagnosis of prostate cancer. Unfortunately, it is organ-specific but not cancer-specific. In addition, some prostate cancers are not clinically-significant and their diagnosis and treatment may lead to overdiagnosis and overtreatment. For these reasons, other markers have been proposed in the last years, such as PCA3 and PHI, but none of these are currently used in the clinical practice on large scale. In the last decade, PSA-IgM and the algorithm iXip have emerged for the diagnosis of prostate cancer and showed to perform well in decreasing the detection of clinically-insignificant prostate cancer and in reducing the number of unnecessary prostate biopsies. This review focuses on data reported in the literature on PSA-IgM and iXip as well as on the future perspectives of their usage in the clinical practice on large scale.

Extranodal Lymphomas: a pictorial review for CT and MRI classification

Extranodal lymphomas represent an extranodal location of both non-Hodgkin and Hodgkin lymphomas. This study aims to evaluate the role of CT and MRI in the assessment of relationships of extranodal lymphomas with surrounding tissues and in the characterization of the lesion. We selected and reviewed ten recent studies among the most recent ones present in literature exclusively about CT and MRI imaging of extranodal lymphomas. Contrast-enhanced computed tomography (CT) is usually the first-line imaging modality in the evaluation of extranodal lymphomas, according to Lugano classification. However, MRI has a crucial role thanks to the superior soft-tissue contrast resolution, particularly in the anatomical region as head and neck. (www.actabiomedica.it)