Discordance between imaging and immunohistochemistry in unilateral primary aldosteronism

Primary aldosteronism subtype discordance between computed tomography and adrenal venous sampling

The primary aldosteronism (PA) subtype is usually confirmed by CT and adrenal venous sampling (AVS). However, the subtype diagnosis by AVS is not necessarily consistent with the subtype diagnosis by CT. Patients with PA who show bilateral lesions (normal-appearing adrenals or bilateral adrenal nodules) on CT but unilateral disease on AVS are often found. The aim of this study was to evaluate whether patients with PA subtype discordance between CT and AVS obtain benefits from unilateral adrenalectomy. We retrospectively analyzed 362 consecutive patients with PA who underwent both CT and adrenocorticotropic hormone-unstimulated AVS at Kanazawa University Hospital. Surgical outcomes for unilateral PA were evaluated according to the criteria of the Primary Aldosteronism Surgical Outcome study. In our study, the success rate of AVS in patients with bilateral lesions on CT was 89% (191/214). Furthermore, the discordance rate between CT and AVS in patients with bilateral lesions on CT was 39% (74/191). After surgery, patients with bilateral lesions on CT but unilateral disease on AVS (n = 17) had a lower complete biochemical success rate than those with unilateral lesions on CT and ipsilateral disease on AVS (n = 30) (41% vs. 80%, p = 0.01), but clinical and biochemical benefits (the complete and partial success combined) were not significantly different between them (76% vs. 93% (p = 0.11) and 70% vs. 90% (p = 0.10), respectively). In conclusion, patients with bilateral lesions on CT but unilateral disease on AVS benefited from surgery, and AVS should be performed for patients who pursue surgical management when the CT findings suggest bilateral lesions.

Primary Aldosteronism: Cardiovascular Outcomes Pre- and Post-treatment

PURPOSE OF REVIEW

Primary aldosteronism (PA) is a common form of hypertension characterized by autonomous aldosterone secretion from one or both adrenal glands. The purpose of this review is to synthesize recent research findings regarding cardiovascular disease risk in PA both pre- and post-targeted therapy.

RECENT FINDINGS

Previously considered a rare disease, recent prevalence studies demonstrate that PA is actually a very common, yet vastly under-diagnosed, etiology of hypertension. Prior to targeted therapy, PA is associated with substantially higher rates of cardiovascular disease compared with essential hypertension. Surgical adrenalectomy is highly effective in curing or improving hypertension as well as mitigating cardiovascular disease risk in patients with unilateral PA. For the remainder of PA patients, MR antagonists are recommended; however, several recent studies have brought into question their effectiveness in improving cardiovascular outcomes. PA is a common cause of hypertension that leads to disproportionately high rates of cardiovascular disease. Future studies are needed to enhance the clinical approach to both identification and treatment of patients with PA to optimize long-term cardiovascular outcomes.

Classification of microadenomas in patients with primary aldosteronism by steroid profiling

In primary aldosteronism (PA) the differentiation of unilateral aldosterone-producing adenomas (APA) from bilateral adrenal hyperplasia (BAH) is usually performed by adrenal venous sampling (AVS) and/or computed tomography (CT). CT alone often lacks the sensitivity to identify micro-APAs. Our objectives were to establish if steroid profiling could be useful for the identification of patients with micro-APAs and for the development of an online tool to differentiate micro-APAs, macro-APAs and BAH. The study included patients with PA (n = 197) from Munich (n = 124) and Torino (n = 73) and comprised 33 patients with micro-APAs, 95 with macro-APAs, and 69 with BAH. Subtype differentiation was by AVS, and micro- and macro-APAs were selected according to pathology reports. Steroid concentrations in peripheral venous plasma were measured by liquid chromatography-tandem mass spectrometry. An online tool using a random forest model was built for the classification of micro-APA, macro-APA and BAH. Micro-APA were classified with low specificity (33%) but macro-APA and BAH were correctly classified with high specificity (93%). Improved classification of micro-APAs was achieved using a diagnostic algorithm integrating steroid profiling, CT scanning and AVS procedures limited to patients with discordant steroid and CT results. This would have increased the correct classification of micro-APAs to 68% and improved the overall classification to 92%. Such an approach could be useful to select patients with CT-undetectable micro-APAs in whom AVS should be considered mandatory.

Adrenal Vein Sampling Lateralization Despite Mineralocorticoid Receptor Antagonists Exposure in Primary Aldosteronism

CONTEXT

Many antihypertensive medications modulate the renin-angiotensin-aldosterone system, possibly skewing the diagnosis and subtyping of primary aldosteronism (PA). Particularly, mineralocorticoid receptor antagonists (MRA) might raise renin and stimulate aldosterone synthesis from nonautonomous areas, potentially obscuring lateralization on adrenal vein sampling (AVS). Withdrawal of MRA in severe PA, however, can precipitate hypokalemia and/or hypertension and therefore is not always practical.

OBJECTIVE

To assess the effects of MRA on the interpretation of AVS data.

DESIGN AND PARTICIPANTS

A cohort study of all PA patients who underwent AVS at University of Michigan between January 2009 and January 2018 was conducted. Demographics, diagnostic, AVS, surgical pathology, and follow-up data were collected retrospectively.

RESULTS

Of 191 patients who underwent AVS, 51 (27%) were exposed to MRA at the time of the procedure. Plasma aldosterone concentration and the daily defined dose of antihypertensives were higher in patients taking vs those not taking MRA. Unilateral PA was more frequent in the MRA group, both precosyntropin and postcosyntropin (P < 0.05). The MRA group included two patients with unsuppressed renin, who demonstrated unequivocal AVS lateralization. To date, 86 patients underwent unilateral adrenalectomy, including 30 patients taking MRA during AVS. The proportion of clinical and biochemical success was not statistically different between patients exposed to and those not exposed to MRA during AVS (P = 0.17 and 0.65, respectively).

CONCLUSION

Our data suggest that conclusive AVS lateralization is often achieved in patients with severe PA despite MRA use.

Diagnosis and treatment of primary aldosteronism: practical clinical perspectives

Primary aldosteronism (PA), the most common form of secondary hypertension, can be either surgically cured or treated with targeted pharmacotherapy. PA is frequently undiagnosed and untreated, leading to aldosterone-specific cardiovascular morbidity and nephrotoxicity. Thus, clinicians should perform case detection testing for PA at least once in all patients with hypertension. Confirmatory testing is indicated in most patients with positive case detection testing results. The next step is to determine whether patients with confirmed PA have a disease that can be cured with surgery or whether it should be treated medically; this step is guided by computed tomography scan of the adrenal glands and adrenal venous sampling. With appropriate surgical expertise, laparoscopic unilateral adrenalectomy is safe, efficient and curative in patients with unilateral adrenal disease. In patients who have bilateral aldosterone hypersecretion, the optimal management is a low-sodium diet and lifelong treatment with a mineralocorticoid receptor antagonist administered at a dosage to maintain a high-normal serum potassium concentration without the aid of oral potassium supplements.

Targeted Molecular Characterization of Aldosterone-Producing Adenomas in White Americans

CONTEXT

Somatic mutations have been identified in more than half of aldosterone-producing adenomas (APAs) through mutation hotspot sequencing. The underlying pathogenesis of inappropriate aldosterone synthesis in the remaining population is still unknown.

OBJECTIVE

To investigate the prevalence and spectrum of somatic mutations in APAs using an aldosterone synthase (CYP11B2) immunohistochemistry (IHC)‒guided next-generation sequencing (NGS) approach.

METHODS

Formalin-fixed paraffin-embedded adrenal tissue from white American patients with primary aldosteronism who underwent adrenalectomy at the University of Michigan was used. Genomic DNA was isolated from 75 APAs (identified by CYP11B2 IHC). NGS was performed to identify somatic mutations by sequencing the entire coding region of a panel of genes mutated in APAs.

RESULTS

Somatic mutations were identified in 66 of 75 APAs (88%). Of the APAs with somatic mutations, six were smaller than coexisting CYP11B2-negative adrenocortical adenomas. The most frequently mutated gene was KCNJ5 (43%), followed by CACNA1D (21%), ATP1A1 (17%), ATP2B3 (4%), and CTNNB1 (3%). In addition to identification of previously reported mutations, we identified five previously unreported mutations (two in KCNJ5, one in ATP1A1, one in ATP2B3, and one in CACNA1D genes). KCNJ5 mutations were more frequent in women (70% vs 24% in men).

CONCLUSION

Comprehensive NGS of CYP11B2-expressing adrenal tumors identified somatic mutations in aldosterone-driving genes in 88% of APAs, a higher rate than in previous studies using conventional approaches.

Advances in adrenal tumors 2018

This review aims to provide clinicians and researchers with a condensed update on the most important studies in the field during 2017. We present the academic output measured by active clinical trials and peer-reviewed published manuscripts. The most important and contributory manuscripts were summarized for each diagnostic entity, with a particular focus on manuscripts that describe translational research that have the potential to improve clinical care. Finally, we highlight the importance of collaborations in adrenal tumor research, which allowed for these recent advances and provide structures for future success in this scientific field.

Immunohistochemical Biomarkers of Adrenal Cortical Neoplasms

Careful morphological evaluation forms the basis of the workup of an adrenal cortical neoplasm. However, the adoption of immunohistochemical biomarkers has added tremendous value to enhance diagnostic accuracy. The authors provide a brief review of immunohistochemical biomarkers that have been used in the confirmation of adrenal cortical origin and in the detection of the source of functional adrenal cortical proliferations, as well as diagnostic, predictive, and prognostic biomarkers of adrenal cortical carcinoma. In addition, a brief section on potential novel theranostic biomarkers in the prediction of treatment response to mitotane and other relevant chemotherapeutic agents is also provided. In the era of precision and personalized medical practice, adoption of combined morphology and immunohistochemistry provides a new approach to the diagnostic workup of adrenal cortical neoplasms, reflecting the evolution of clinical responsibility of pathologists.

The Many Faces of Primary Aldosteronism and Cushing Syndrome: A Reflection of Adrenocortical Tumor Heterogeneity

Adrenal cortical tumors constitute a heterogeneous group of neoplasms with distinct clinical, morphological, and molecular features. Recent discoveries of specific genotype–phenotype correlations in adrenal cortical adenomas have transformed our understanding of their respective endocrine syndromes. Indeed, a proportion of patients with primary aldosteronism are now known to harbor adrenal cortical adenomas with heterogeneous molecular alterations (KCNJ5, ATP1A1, ATP2B3, and CACNA1D) involving the calcium/calmodulin kinase signaling pathway. Several lines of evidence suggest that KCNJ5-mutant aldosterone-producing adenomas have distinct clinicopathological phenotype compared to those harboring ATP1A1, ATP2B3, and CACNA1D mutations. Benign adrenal cortical tumors presenting with Cushing syndrome often have diverse mutations (PRKACA, PRKAR1A, GNAS, PDE11A, and PDE8B) involving the cyclic AMP signaling pathway. In addition to cortisol-producing adenomas, bilateral micronodular adrenocortical disease and primary bilateral macronodular adrenal hyperplasia (PBMAH) have also expanded the spectrum of benign neoplasms causing adrenal Cushing disease. The recent discovery of inactivating ARMC5 germline mutations in PBMAH has challenged the old belief that this disorder is mainly a sporadic disease. Emerging evidence suggests that PBMAH harbors multiple distinct clonal proliferations, reflecting the heterogeneous genomic landscape of this disease. Although most solitary adrenal cortical tumors are sporadic, there is an increasing recognition that inherited susceptibility syndromes may also play a role in their pathogenesis. This review highlights the molecular and morphological heterogeneity of benign adrenal cortical neoplasms, reflected in the diverse presentations of primary aldosteronism and adrenal Cushing syndrome.

The Many Faces of Primary Aldosteronism and Cushing Syndrome: A Reflection of Adrenocortical Tumor Heterogeneity

Adrenal cortical tumors constitute a heterogeneous group of neoplasms with distinct clinical, morphological, and molecular features. Recent discoveries of specific genotype-phenotype correlations in adrenal cortical adenomas have transformed our understanding of their respective endocrine syndromes. Indeed, a proportion of patients with primary aldosteronism are now known to harbor adrenal cortical adenomas with heterogeneous molecular alterations (KCNJ5, ATP1A1, ATP2B3, and CACNA1D) involving the calcium/calmodulin kinase signaling pathway. Several lines of evidence suggest that KCNJ5-mutant aldosterone-producing adenomas have distinct clinicopathological phenotype compared to those harboring ATP1A1, ATP2B3, and CACNA1D mutations. Benign adrenal cortical tumors presenting with Cushing syndrome often have diverse mutations (PRKACA, PRKAR1A, GNAS, PDE11A, and PDE8B) involving the cyclic AMP signaling pathway. In addition to cortisol-producing adenomas, bilateral micronodular adrenocortical disease and primary bilateral macronodular adrenal hyperplasia (PBMAH) have also expanded the spectrum of benign neoplasms causing adrenal Cushing disease. The recent discovery of inactivating ARMC5 germline mutations in PBMAH has challenged the old belief that this disorder is mainly a sporadic disease. Emerging evidence suggests that PBMAH harbors multiple distinct clonal proliferations, reflecting the heterogeneous genomic landscape of this disease. Although most solitary adrenal cortical tumors are sporadic, there is an increasing recognition that inherited susceptibility syndromes may also play a role in their pathogenesis. This review highlights the molecular and morphological heterogeneity of benign adrenal cortical neoplasms, reflected in the diverse presentations of primary aldosteronism and adrenal Cushing syndrome.