A diagnostic approach to adrenal cortical lesions

How to Differentiate Benign from Malignant Adrenocortical Tumors?

Simple Summary

Adrenocortical carcinoma is a rare cancer with a poor prognosis. Adrenal tumors are, however, commonly identified in clinical practice. Discrimination between benign and malignant adrenal tumors is of great importance to determine the appropriate treatment and follow-up strategy. This review summarizes the current diagnostic strategies and challenges to distinguish benign from malignant adrenal lesions. We will focus both on radiological and biochemical assessments, enabling diagnosis of the adrenal lesion preoperatively, and on histopathological and a wide variety of molecular assessments that can be done after surgical removal of the adrenal lesion. Furthermore, new non-invasive strategies such as liquid biopsies, in which blood samples are used to study circulating tumor cells, tumor DNA and microRNA, will be addressed in this review.

Abstract

Adrenocortical carcinoma (ACC) is a rare cancer with a poor prognosis. Adrenal incidentalomas are, however, commonly identified in clinical practice. Discrimination between benign and malignant adrenal tumors is of great importance considering the large differences in clinical behavior requiring different strategies. Diagnosis of ACC starts with a thorough physical examination, biochemical evaluation, and imaging. Computed tomography is the first-level imaging modality in adrenal tumors, with tumor size and Hounsfield units being important features for determining malignancy. New developments include the use of urine metabolomics, also enabling discrimination of ACC from adenomas preoperatively. Postoperatively, the Weiss score is used for diagnosis of ACC, consisting of nine histopathological criteria. Due to known limitations as interobserver variability and lack of accuracy in borderline cases, much effort has been put into new tools to diagnose ACC. Novel developments vary from immunohistochemical markers and pathological scores, to markers at the level of DNA, methylome, chromosome, or microRNA. Molecular studies have provided insights into the most promising and most frequent alterations in ACC. The use of liquid biopsies for diagnosis of ACC is studied, although in a small number of patients, requiring further investigation. In this review, current diagnostic modalities and challenges in ACC will be addressed.

A Diagnostic Approach to Adrenocortical Tumors

Adrenocortical tumors range from primary bilateral micronodular or macronodular forms of adrenocortical disease to conventional adrenocortical adenomas and carcinomas. Accurate classification of these neoplasms is critical given the varied pathogenesis, clinical behavior, and outcome of these different lesions. Confirmation of adrenocortical origin, diagnosing malignancy, providing relevant prognostic information in adrenocortical carcinoma, and correlation of laboratory results with clinicopathologic findings are among the important responsibilities of pathologists who evaluate these lesions. This article focuses on a practical approach to the evaluation of adrenocortical tumors with an emphasis on clinical and imaging findings, morphologic characteristics, and multifactorial diagnostic schemes and algorithms.

Challenges in surgical pathology of adrenocortical tumours

Adrenocortical carcinomas are rare tumours that can be diagnostically challenging. Numerous multiparametric scoring systems and diagnostic algorithms have been proposed to differentiate adrenocortical adenoma from adrenocortical carcinoma. Adrenocortical neoplasms must also be differentiated from other primary adrenal tumours, such as phaeochromocytoma and unusual primary adrenal tumours, as well as metastases to the adrenal gland. Myxoid, oncocytic and sarcomatoid variants of adrenocortical tumours must be recognized so that they are not confused with other tumours. The diagnostic criteria for oncocytic adrenocortical carcinoma are different from those for conventional adrenocortical carcinomas. Adrenocortical neoplasms in children are particularly challenging to diagnose, as histological features of malignancy in adrenocortical neoplasms in adults may not be associated with aggressive disease in the tumours of children. Recent histological and immunohistochemical studies and more comprehensive and integrated genomic characterizations continue to advance our understanding of the tumorigenesis of these aggressive neoplasms, and may provide additional diagnostic and prognostic utility and guide the development of therapeutic targets.

Clinicopathological correlates of adrenal Cushing's syndrome

Endogenous Cushing's syndrome is a rare endocrine disorder that incurs significant cardiovascular morbidity and mortality, due to glucocorticoid excess. It comprises adrenal (20%) and non-adrenal (80%) aetiologies. While the majority of cases are attributed to pituitary or ectopic corticotropin (ACTH) overproduction, primary cortisol-producing adrenal cortical lesions are increasingly recognised in the pathophysiology of Cushing's syndrome. Our understanding of this disease has progressed substantially over the past decade. Recently, important mechanisms underlying the pathogenesis of adrenal hypercortisolism have been elucidated with the discovery of mutations in cyclic AMP signalling (PRKACA, PRKAR1A, GNAS, PDE11A, PDE8B), armadillo repeat containing 5 gene (ARMC5) a putative tumour suppressor gene, aberrant G-protein-coupled receptors, and intra-adrenal secretion of ACTH. Accurate subtyping of Cushing's syndrome is crucial for treatment decision-making and requires a complete integration of clinical, biochemical, imaging and pathology findings. Pathological correlates in the adrenal glands include hyperplasia, adenoma and carcinoma. While the most common presentation is diffuse adrenocortical hyperplasia secondary to excess ACTH production, this entity is usually treated with pituitary or ectopic tumour resection. Therefore, when confronted with adrenalectomy specimens in the setting of Cushing's syndrome, surgical pathologists are most commonly exposed to adrenocortical adenomas, carcinomas and primary macronodular or micronodular hyperplasia. This review provides an update on the rapidly evolving knowledge of adrenal Cushing's syndrome and discusses the clinicopathological correlations of this important disease.

Giant adrenal myelolipoma

A fifty-two years old male presenting with a history of abdominal pain of six months duration was found on investigation to have a large non-functioning adrenal mass. Adrenal myelolipoma was diagnosed preoperatively and surgical resection was carried out. Only a small number of cases of giant adrenal myelolipoma (>3500 grams) have been reported. A brief review of literature is done.

Adrenocortical carcinoma and synchronous malignancies

Objective: Adrenocortical carcinoma (ACC) is an aggressive tumor that accounts for 0.02% of all reported cancers. ACC commonly arises in a sporadic manner, but may also manifest as part of a familial syndrome. Regardless of the setting, ACC rarely arises concurrent with other malignant tumors.

Methods: In this report we describe a 32-year-old woman who on work-up for abnormal vaginal bleeding was diagnosed with synchronous uterine adenocarcinoma, ovarian adenocarcinoma and ACC. We also provide a literature review of the past 20 years to identify other patients with ACC and synchronous malignant tumors, and those with familial syndromes associated with an increased risk of developing ACC.

Results and Conclusions: To our knowledge this is the first report of a patient with synchronous malignant tumors of the uterus, ovary and adrenal gland. Review of the literature revealed only 5 other cases in which a patient had concurrent ACC and malignant tumors in other organs.

Aortic intramural hematoma associated with metastatic carcinoma

We present a case of aortic intramural hematoma, a variant of aortic dissection, with metastatic carcinoma invasion within the aortic wall and pseudolumen. An elderly male patient with a history of controlled hypertension initially experienced chest pain. A computed tomographic scan revealed aortic intramural hematoma; thus, conservative therapy was performed. One and a half months later, tumors in both adrenal glands and the lumbar vertebra were discovered. The primary site was not identified, and the patient died following septic shock 1 month later. An autopsy revealed intramural hematoma throughout the aorta, as well as systemic metastases of adrenocortical carcinoma with invasion into the aortic wall and formation of a pseudolumen accompanied by disruption of the vasa vasorum. As far as we know, this is the second case of aortic dissection associated with metastatic carcinoma. The highly aggressive nature of the tumor cells was demonstrated by high mitotic ratio and Ki-67 labeling index. The tumor was also positive for matrix metalloproteinase-12, thus suggesting disruption of the aortic media.

Diagnosis and management of pediatric endocrine neoplasms

PURPOSE OF REVIEW

To guide the clinician in the diagnostic evaluation of endocrine neoplasms, to distinguish between benign and malignant and determine when surgical referral is indicated.

RECENT FINDINGS

Thyroid nodules are uncommon but malignant in as many as 27% of patients. Fine needle aspiration should be considered in adolescents, in which accuracy is as high as 90%; surgical resection should be undertaken in all preadolescents (<13 years) with a thyroid nodule. Prognosis for most primary thyroid malignancies is favorable. Primary hyperparathyroidism is rare and due to an adenoma in up to 70% of patients. Surgical resection carries a cure rate of 95% with the use of intraoperative parathyroid hormone assays. Adrenal neoplasms cover a wide spectrum of disorder. They are functional in 95% of patients and require a thorough diagnostic evaluation prior to surgical resection. Malignant lesions of the adrenal gland carry a poor prognosis when complete surgical resection cannot be achieved. Carcinoids are rare neuroendocrine neoplasms, primarily of the appendix, associated with carcinoid syndrome in 10% of patients. The indolent course warrants aggressive surgical control.

SUMMARY

Endocrine neoplasms are unusual in the pediatric population. Their presence should raise concern about a multiple endocrine neoplasia syndrome and appropriate diagnostic and endocrine work-up. Most neoplasms will require surgical resection.

Adrenal incidentalomas and subclinical Cushing's syndrome: diagnosis and treatment

PURPOSE OF REVIEW

Adrenal incidentaloma has become a frequent clinical dilemma. Even in the absence of specific clinical features of Cushing's syndrome, adrenocortical incidentalomas may display steroid secretory activity at different degrees. The recognition of endocrine and metabolic dysfunctions associated with subclinical hypercortisolism leads to current awareness about its potential consequences.

RECENT FINDINGS

Different protocols and threshold values to define normal cortisol secretion and diagnosis of subclinical Cushing's syndrome have been proposed, including recent practice guidelines for the diagnosis of overt Cushing's syndrome. Follow-up studies have provided additional data about the natural course of the disease and related cardiovascular and metabolic consequences. The study of bilateral adrenocorticotropin-independent macronodular adrenocortical hyperplasia in some familial cases offers a new approach to understanding the spectrum of subclinical cortisol hypersecretion.

SUMMARY

The prevalence of subclinical hypercortisolism may be higher than previously reported as more sensitive diagnostic criteria are now recommended. The absence of a single gold standard test, the diversity of diagnostic criteria and the requirement of subsequent meticulous biochemical evaluations before a decision for treatment represent a challenge for the clinical management of this condition.