Large Adrenal Incidentalomas Require a Dedicated Diagnostic Procedure

[18F]FDG-PET/CT in adrenal lesions: diagnostic performance in different clinical settings

PURPOSE

Data regarding [18F]FDG-PET/CT for the characterization of adrenal lesions are limited. Most of the studies proposed the tumor-to-liver maximum standardized uptake values (SUVratio) > 1.5 as the best cut off to predict malignancy. The aim of the study was to calculate the optimum cut off in a heterogeneous population with adrenal lesions and evaluate the diagnostic performance SUVratio >1.5.

PATIENTS AND METHODS

Retrospective analysis of adrenal lesions undergoing [18F]FDG-PET/CT (2013-2022) for different reasons (atypical adrenal incidentalomas, extra adrenal tumor staging). The diagnosis of benignity was assessed by: (i) histology; (ii) stability or minimal diameter increase (<20%/<5 mm) on 12-months follow-up for non-operated patients. The optimal SUVratio and performance of SUVratio >1.5 were calculated by ROC curves.

RESULTS

Forty-two consecutive lesions (diameter 36.1 ± 20.3 mm, 6 bilateral) underwent [18F]FDG-PET/CT (19F, age 61.2 ± 11.7 years). Twenty-nine lesions were benign, 11 malignant [8 metastases (2 bilateral) and 1 adrenocortical carcinoma (ACC)] and 2 pheochromocytomas. The SUVratio cut-off in our population was 1.55 (Sn 100%, Sp 73.7%, AUC 0.868), with similar values excluding pheochromocytomas and metastases (SUVratio cut-off 1.49, Sn 100%, Sp 96.3%, AUC 0.988). The SUVratio cut-off of 1.5 showed 100% Sn, 87% Sp, 73% PPV, and 100% NPV.

CONCLUSION

[18F]FDG-PET/CT could help in decision making process avoiding unnecessary surgery. The SUVratio cut-off of 1.5 has a good performance in a heterogenous population.

Impact of Size Thresholds on the Diagnosis of Incidental Adrenal Lesions: A Systematic Review and Meta-Analysis

BACKGROUND

Preferred size-threshold recommendations for management of incidental adrenal lesions remain controversial.

PURPOSE

This meta-analysis aimed to compare the diagnostic accuracy of different size thresholds for detecting malignancy in patients with incidental adrenal lesions on imaging.

MATERIALS AND METHODS

A systematic review of MEDLINE, Embase, Scopus, the Cochrane Library, and the gray literature, covering the period from inception to September 2021, was performed. Studies with >10 patients evaluating the diagnostic accuracy of imaging size thresholds for detecting malignancy in patients with incidental adrenal lesions and no prior history of cancer were included. Study, clinical, imaging, and accuracy data for eligible studies were independently acquired by two reviewers. Primary meta-analysis was performed using a bivariate mixed-effects regression model. Risk of bias was evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool.

RESULTS

From 2,690 citations, 40 studies (9,794 patients with mean age ranging from 41 to 66 years) were included. Most (36 of 40) were retrospective single-center studies. CT with or without MRI served as the index test(s). Sensitivity and specificity values, respectively, by size threshold used in the included studies were as follows: 85% (95% confidence interval [CI] 74%-91%) and 39% (95% CI 23%-57%) for 3-cm thresholds; 85% (95% CI 78%-90%) and 75% (95% CI 62%-85%) for 4-cm thresholds; 70% (95% CI 56%-81%) and 74% (95% CI 59%-85%) for 5-cm thresholds; and 75% (95% CI 67%-82%) and 77% (95% CI 62%-87%) for 6-cm thresholds. No cause for variability in sensitivity or specificity was identified on subgroup analysis of the 4-cm threshold. Nearly half of the studies (19 of 40) had at least one QUADAS-2 domain with a high risk of bias.

CONCLUSIONS

A 4-cm size threshold demonstrates the highest combined sensitivity and specificity, with a preserved specificity compared with higher size thresholds, but with a trend toward improved sensitivity. Future research reevaluating 4-5 cm size thresholds while excluding characteristically benign lesions by imaging may help redefine a size threshold that has improved specificity but preserved sensitivity, compared with the existing 4-cm threshold.

The Diagnostic Value of 18F-FDG PET/CT Scan in Characterizing Adrenal Tumors

CONTEXT

Imaging plays an important role in the characterization of adrenal tumors, but findings might be inconclusive. The clinical question is whether 18F fluodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) is of diagnostic value in this setting.

OBJECTIVE

This meta-analysis was aimed at the diagnostic value of 18F-FDG PET/CT in differentiating benign from malignant adrenal tumors discovered either as adrenal incidentaloma or during staging or follow-up of oncologic patients.

DATA SOURCES

PubMed, EMBASE, Web of Science, and Cochrane Library were searched to select articles between 2000 and 2021.

STUDY SELECTION

We included studies describing the diagnostic value of 18F-FDG PET/CT in adult patients with an adrenal tumor. Exclusion criteria were 10 or fewer participants, insufficient data on histopathology, clinical follow-up, or PET results. After screening of title and abstract by 2 independent reviewers, 79 studies were retrieved, of which 17 studies met the selection criteria.

DATA EXTRACTION

Data extraction using a protocol and quality assessment according to QUADAS-2 was performed independently by at least 2 authors.

DATA SYNTHESIS

A bivariate random-effects model was applied using R (version 3.6.2.). Pooled sensitivity and specificity of 18F-FDG PET/CT for identifying malignant adrenal tumors was 87.3% (95% CI, 82.5%-90.9%) and 84.7% (95% CI, 79.3%-88.9%), respectively. The pooled diagnostic odds ratio was 9.20 (95% CI, 5.27-16.08; P < .01). Major sources of heterogeneity (I2, 57.1% [95% CI, 27.5%-74.6%]) were in population characteristics, reference standard, and interpretation criteria of imaging results.

CONCLUSIONS

18F-FDG PET/CT had good diagnostic accuracy for characterization of adrenal tumors. The literature, however, is limited, in particular regarding adrenal incidentalomas. Large prospective studies in well-defined patient populations with application of validated cutoff values are needed.

Adrenal Tumors in Young Adults: Case Reports and Literature Review

The current high detection rate of adrenal tumors (4–10% of general population) is attributable to a widespread use of variety of imaging studies, especially a computed tomography. Most of them represent clinically silent and biologically indolent incidentalomas, but some adrenal tumors may pose a significant clinical challenge. Thus, in every patient with an adrenal tumor, a decision on further management is made after careful hormonal and radiological evaluation. All hormonally active tumors and those with radiological features suggesting malignancy are qualified for surgery. Approximately 80% of adrenal tumors are adrenocortical adenomas, hypertrophy, or nodular adrenocortical hyperplasia. Other histopathological diagnoses include pheochromocytoma, adrenocortical carcinoma, metastases, mesenchymal tumors, lymphomas, cysts, and ganglioneuromas. Adrenal tumors are more commonly diagnosed and better studied in elderly patients. In younger patients, under 40 years old, focal adrenal lesions are relatively rare, and histological distribution of diagnoses differs from that in elderly individuals. Younger patients are more likely to display endocrine symptoms, which raise the suspicion of an adrenal mass. In the current study, we present a case series of seven adrenal tumors occurring in young patients. The cases presented below, along with the literature review, demonstrate that the diagnosis and treatment of adrenal tumors are crucial due to endocrinopathy-derived complications and a potential risk of malignancy.

Adrenocortical Carcinoma Discovered with Point-of-care Ultrasound

Case Presentation

A 34-year-old woman presented to the emergency department with bilateral lower extremity edema and shortness of breath. She had been seen by her primary care provider. Lab work and a follow-up with endocrinology had been unrevealing. Using point-of-care ultrasound we identified a cystic mass in the right upper quadrant prompting further imaging.

Discussion

Abdominal and pelvic computed tomography confirmed a mass in the right posterior liver, which was later identified as an adrenocortical carcinoma. Ultrasound is an important diagnostic tool in the setting of lower extremity edema and can be used to assess for heart failure, liver failure, obstructive nephropathy, venous thrombosis, and soft tissue infection. In this case, ultrasound helped expedite the diagnosis and treatment of a rare malignancy.

[Rare Findings in the Workup of Abdominal Pain]

Rare Findings in the Workup of Abdominal Pain Abstract. Atypical symptoms such as abdominal discomfort or epigastric pain can be misleading in patients presenting conditions such as obesity, type 2 diabetes, hypertension or ischemic heart disease. In this article we describe two cases of impressively large adrenal masses discovered only several years after the appearance of nonspecific symptoms.

Cancer risk in adrenalectomy: are adrenal lesions equal or more than 4 cm a contraindication for laparoscopy?

Background

Some authors consider adrenal lesions size of less than 4 cm as a positive cut-off limit to set the indications for minimally invasive surgery due to a lower risk of malignancy. Aim of this study is to report the risk of cancer for adrenal lesions measuring 4 cm or more in diameter, assessed as benign at preoperative workup (primary outcome), and to evaluate the feasibility and safety of laparoscopic adrenalectomy (LA) in these cases (secondary outcome).

Methods

From January 1994 to February 2019, 579 patients underwent adrenalectomy. Fifty patients with a preoperative diagnosis of primary adrenal cancer or metastases were excluded. The remaining 529 patients were included and divided in five subgroups based on adrenal lesion size at definitive histology: group A, 4–5.9 cm (137 patients); group B, 6–7.9 cm (64 patients); group C, 8–9.9 cm (13 patients); group D, ≥ 10 cm (11 patients); group E, < 4 cm (304 patients). Each group was further divided based on diagnosis of benign or malignant lesions at definitive histology.

Results

Four (2.9%) malignant lesions were observed in group A, 5 (7.8%) in group B, 2 (15.4%) in Groups C and D (18.2%) and 13 (4.3%) in Group E. Comparing the cancer risk among the groups, no statistically significant differences were observed. Operative time increased with increasing lesion size. However, no statistically significant differences were observed between benign and malignant lesions in each group comparing operative time, conversion and complication rates, postoperative hospital stay and mortality rate.

Conclusions

Adrenal lesions measuring 4 cm or more in diameter are not a contraindication for LA neither in terms of cancer risk nor of conversion and morbidity rates, even if the operative time increases with increasing adrenal lesion diameter. Further prospective studies with a larger number of patients are required to draw definitive conclusions.

Management of adrenal incidentalomas: Working through uncertainty

The European society of endocrinology, in association with the European network for the study of adrenal tumors, published recommendations for the diagnosis and treatment of adrenal incidentalomas in 2016. A thorough and critical analysis of the literature was performed to establish evidence-based recommendations and expert suggestions with the aim of avoiding 'over-diagnosis' and 'over-treatment' and to reduce unnecessary investigations, surgery and follow-up. The purpose of this review is to reconsider several recommendations that are open to debate, such as imaging of adrenal incidentalomas, diagnosis of pheochromocytoma, diagnosis and treatment of autonomous cortisol-secreting tumors, investigations of bilateral AI and follow-up of non-operated AIs, based on studies published after the release of the recommendations.