Renal Function Evolution and Hypoaldosteronism Risk After Unilateral Adrenalectomy for Primary Aldosteronism

Few studies demonstrated a percentage decrease in the estimated glomerular filtration rate (eGFR) at a single time and the rate of hypoaldosteronism after adrenalectomy for primary aldosteronism (PA). Our aim was to investigate the evolution of renal function and the hypoaldosteronism risk after adrenalectomy for PA. Aldosterone, renin, eGFR, and electrolyte levels were determined before and at 1 week, 1, 3 and 6 months after unilateral adrenalectomy in 94 PA patients (40 men and 54 women). The main outcome was the postoperative eGFR decline using analysis of covariance with the preoperative eGFR as a covariate. eGFR decreased during first postoperative week compared to 3 months before surgery. During the first 6 months, eGFR remained stable at similar levels to the first week after surgery. Age (p=0.001), aldosterone levels (p=0.021) and eGFR 3 months before surgery (p+<+0.0001) had a significant correlation with eGFR during first postoperative week. High aldosterone levels at diagnosis were correlated with decline in renal function in the univariate model (p=0.033). In the multivariate analysis, aldosterone levels at diagnosis had a tendency to be an independent predictor of renal function after surgery (p=0.059). Postoperative biochemical hypoaldosteronism was diagnosed in 48% of the cases after adrenalectomy, but prolonged hyperkalemia occurred in only 4 cases (4.5%). Our findings showed a decrease of eGFR after unilateral adrenalectomy for PA. Additionally, aldosterone levels at diagnosis correlated with postoperative renal function. Postoperative biochemical hypoaldosteronism occurred in almost half of the patients, but prolonged hyperkalemia with fludrocortisone replacement was less frequent.

Intraoperative radiofrequency ablation for unresectable abdominal paraganglioma: a case report

For pheochromocytoma and paraganglioma (PPGL), the efficacy of percutaneous ablative therapies in achieving control of metastatic tumors measuring <3 cm had been demonstrated in only few reports, and intraoperative radiofrequency ablation (RFA) of locally invasive primary PPGLs has not been reported. We presented the case of a 31-year-old man who had a 9-cm functioning unresectable PPGL. He was treated with 13 cycles of cytotoxic chemotherapy without objective tumor response, according to the Response Evaluation Criteria in Solid Tumors (RECIST). Subsequently, magnetic resonance imaging revealed a 9.0 × 8.6 × 6.0-cm retroperitoneal mass that extended to the inferior portion of the inferior vena cava, the inferior mesenteric artery, and the infrarenal aorta. Biochemical evaluation demonstrated high level of plasma normetanephrine (20.2 nmol/L, normal range <0.9 nmol/L). Genetic investigation showed the germline pathogenic variant c.1591delC (p. Ser198Alafs*22) in the SDHB gene. I131-metaiodobenzylguanidine scintigraphy was negative and Ga68-dotatate PET-CT scan showed high tumor uptake without distant metastases. On open laparotomy, tumor debulking was not possible. Therefore, intraoperative RFA was performed by a highly experienced team of interventional radiologists. At 12 months after the RFA, the tumor volume decreased from 208 to 45 mL (78%), plasma normetanephrine decreased from 20.2 to 2.6 nmol/L (87%), and the doxazosin dose was reduced from 16 to 8 mg/day. To our best knowledge, this was the first report on intraoperative RFA that markedly reduced the size of a large primary unresectable PPGL, along with clinical and biochemical responses.

Contralateral suppression in adrenal venous sampling predicts clinical and biochemical outcome in primary aldosteronism

CONTEXT

The role for hormone parameters at adrenal venous sampling (AVS) in predicting clinical and biochemical outcome remains controversial.

OBJECTIVE

To investigate the impact of hormone parameters at AVS under cosyntropin stimulation on lateralization and on complete biochemical and clinical outcome.

METHODS

We retrospectively evaluated 150 sequential AVS under cosyntropin infusion. Bilateral successful cannulation rate was 83.3% (n = 140), 47.9% bilateral and 52.1% unilateral. The lateralization index (LI), aldosterone/cortisol ratio (A/C) in the dominant adrenal vein (AV), relative aldosterone secretion index (RASI = A/C in AV divided by A/C in inferior vena cava) were assessed. The contralateral suppression (CS) percentage was defined by (1 - nondominant RASI) *100.

RESULTS

A nondominant RASI <0.5 (CS >50%) had 86.84% sensitivity and 92.96% specificity to predict contralateral lateralization. An A/C ratio in dominant AV >5.9 (74.67% sensitivity and 80% specificity) and dominant RASI >4.7 (35.21% sensitivity and 88.06% specificity) had a worst performance to predict ipsilateral lateralization. Complete biochemical and clinical cure were significantly more frequent in the patients with CS >50% [98.41% vs. 42.86% (p < 0.001) and 41.94% vs. 0% (p < 0.001)]. CS correlated with high aldosterone at diagnosis (p < 0.001) and low postoperative aldosterone levels at 1 month (p = 0.019). Postoperative biochemical hypoaldosteronism was more frequent in patients with CS >50% (70% vs. 16.67%, p = 0.014). In multivariable analysis, a CS >50% was associated with complete biochemical cure (OR 125, 95%CI 11.904-5,000; p = 0.001) and hypertension remission (OR 12.19, 95%CI 2.074-250; p = 0.023).

CONCLUSION

A CS >50% was an independent predictor of complete clinical and biochemical cure. Moreover, it can predict unilateral PA and postoperative biochemical hypoaldosteronism. Our findings underscore the usefulness of CS for clinical decision-making.

Efficacy of Oral Furosemide Test for Primary Aldosteronism Diagnosis

Context

Confirmatory tests represent a fundamental step in primary aldosteronism (PA) diagnosis, but they are laborious and often require a hospital environment due to the risks involved.

Objective

To evaluate the efficacy of oral furosemide as a new confirmatory test for PA diagnosis.

Methods

We prospectively evaluated the diagnostic performance of 80 mg of oral furosemide in 64 patients with PA and 22 with primary hypertension (controls). Direct renin concentration (DRC) was measured before, and 2 hours and 3 hours after the oral furosemide. In addition, the oral furosemide test was compared with 2 other confirmatory tests: the furosemide upright test (FUT) and saline infusion test (SIT) or captopril challenge test (CCT) in all patients with PA.

Results

The cut-off of 7.6 µU/mL for DRC at 2 hours after oral furosemide had a sensitivity of 92%, specificity of 82%, and accuracy of 90% for PA diagnosis. In 5 out of 6 controls with low-renin hypertension, which might represent a PA spectrum, renin remained suppressed. Excluding these 6 controls with low-renin hypertension, the DRC cut-off of 10 µU/mL at 2 hours after oral furosemide had a sensitivity of 95.3%, specificity of 93.7% and accuracy of 95% for PA diagnosis. DRC after 3 hours of oral furosemide did not improve diagnostic performance. Using the cut-off of 10 µU/mL, the oral furosemide test and the FUT were concordant in 62 out of 64 (97%) patients with PA. Only 4 out of 64 cases with PA (6.4%) ended the oral furosemide test with potassium <3.5 mEq/L. Hypotension was not evidenced in any patient with PA during the test.

Conclusion

The oral furosemide test was safe, well-tolerated and represents an effective strategy for PA investigation.

Evidence for a Founder Effect of SDHB Exon 1 Deletion in Brazilian Patients with Paraganglioma

BACKGROUND

Limited information is available concerning the genetic spectrum of pheochromocytomas and paragangliomas (PPGL) patients in South America. Germline SDHB large deletions are very rare worldwide, but most of the individuals harboring the SDHB exon 1 deletion were originated from the Iberian Peninsula. Our aim was to investigate the spectrum of SDHB genetic defects in a large cohort of Brazilian patients with PPGLs.

METHODS

The genetic investigation of 155 index PPGL patients was performed by Sanger DNA sequencing, multiplex ligation-dependent probe amplification, and/or target next-generation sequencing panel. Common ancestrality was investigated by microsatellite genotyping with haplotype reconstruction, and analysis of deletion breakpoint.

RESULTS

Among 155 index patients, heterozygous germline SDHB pathogenic or likely pathogenic variants (PV/LPVs) were identified in 22 cases (14.2%). Interestingly, the heterozygous SDHB exon 1 complete deletion was the most frequent genetic defect in SDHB, being identified in 8 out of 22 (36%) of the patients. Haplotype analysis of 5 SDHB flanking microsatellite markers demonstrated a significant difference in haplotype frequencies in a case-control permutation test (p = 0.03). More precisely, 3 closer/informative microsatellites were shared by 6 out of 8 apparently unrelated cases (75%) (SDHB-GATA29A05-D1S2826-D1S2644 | SDHB-186-130-213), which was observed in only 1 chromosome (1/42) without SDHB exon 1 deletion (X2= 29.43; p < 0.001). Moreover, all cases with SDHB exon 1 deletion had the same gene breakpoint pattern of a 15,678 bp deletion previously described in the Iberian Peninsula, indicating a common origin.

CONCLUSION

The germline heterozygous SDHB exon 1 deletion was the most frequent genetic defect in the Brazilian PPGL cohort. Our findings demonstrated a founder effect for the SDHB exon 1 deletion in Brazilian patients with paragangliomas.

Intraindividual variability of serum aldosterone and its implication for primary aldosteronism screening

CONTEXT

Primary aldosteronism (PA) screening relies on an elevated aldosterone to renin ratio with a minimum aldosterone level, which varies from 10 to 15 ng/dL (277 to 415.5 pmol/L) using immunoassay.

AIM

To evaluate intraindividual coefficient of variation (CV) of aldosterone and aldosterone to direct renin concentration ratio (A/DRC) and its impact on PA screening.

METHODS

A total of 671 aldosterone and DRC measurements were performed by the same chemiluminescence assays in a large cohort of 216 patients with confirmed PA and at least two screenings.

RESULTS

The median intraindividual CV of aldosterone and A/DRC was 26.8% and 26.7%. Almost 40% of the patients had at least one aldosterone level <15 ng/dL, 19.9% had at least two aldosterone levels <15 ng/dL and 16.2% had mean aldosterone levels <15 ng/dL. A lower cut-off of 10 ng/dL was associated with false negative rates for PA screening of 14.3% for a single aldosterone measurement, 4.6% for two aldosterone measurements and only 2.3% for mean aldosterone levels. Considering the minimum aldosterone, true positive rate of aldosterone thresholds was 85.7% for 10 ng/dL and 61.6% for 15 ng/dL. An A/DRC >2 ng/dL/µIU/mL had a true positive rate for PA diagnosis of 94.4% and 98.4% when based on one or two assessments, respectively. CV of aldosterone and A/DRC were not affected by sex, use of interfering anti-hypertensive medications, PA lateralization, hypokalemia, age and number of hormone measurements.

CONCLUSION

Aldosterone concentrations had a high CV in PA patients, which results in an elevated rate of false negative test in a single screening for PA. Therefore, PA screening should be based in at least two screenings with concomitant aldosterone and renin measurements.

RF09 | PSUN29 Evidence for a Founder Effect of SDHB Exon 1 Complete Deletion in Brazilian Patients with Paraganglioma

Background

Pheochromocytomas and paragangliomas (PPGLs) have the highest degree of heritability among endocrine tumors. Currently, ∼40% of PPGL individuals have a genetic germline pathogenic variant and exist at least 12 different genetic syndromes related to these tumors. Pathogenic variants in the Succinate Dehydrogenase Complex Subunit B (SDHB) gene account for about 10% of PPGL cases. Moreover, SDHB pathogenic variants are the most well-established risk factor to predict metastatic disease (40%-50% of cases). Germline SDHB large deletions are very rare worldwide, but SDHB exon 1 deletion has been reported in patients with PPGLs from Portugal and Spain. Indeed, a putative founder effect for SDHB exon 1 deletion was suggested in PPGL patients from Iberian Peninsula.

Aim

To investigate a putative founder effect for SDHB exon 1 deletion.

Methods

Eighteen unrelated Brazilian patients with germline heterozygous SDHB pathogenic variants were included. Additionally, two unrelated individuals with SDHB exon 1 complete deletion from Argentina were studied. SDHB pathogenic variants were investigated by automated SAGER sequencing, multiplex ligation-dependent probe amplification (SALSA MLPA Probemix P226 SDH) and/or high-throughput sequencing. Five SDHB flanking microsatellite markers at chromosome 1p (D1S2697, GATA29A05, D1S2826, D1S2644, and D1S199) were used to investigate if patients carrying this deletion have a common origin. Haplotypes were reconstructed using the PHASE algorithm (v. 2.1). A control group comprising 26 unrelated Brazilian individuals was also studied.

Results

Among 18 Brazilian patients with germline SDHB pathogenic variants, heterozygous SDHB exon 1 complete deletion was identified in 6 of them (33% of the cases). The remaining 12 patients presented intragenic SDHB pathogenic variants without hotspot location. All Brazilian index patients with SDHB exon 1 deletion presented with paraganglioma, located mostly in the abdomen (4 abdominal; one thoracic; two head and neck and one colonic). Median age was 31.5 years and metastatic disease occurred in 3 (50%) of them. Haplotype analysis showed that 4 apparently unrelated Brazilian patients (4 out of 6 cases, 67%) shared a common allele (SDHB-GATA29A05-D1S2826-D1S2644-D1S199 | SDHB-186-130-213-102), which was not seen in chromosomes without the SDHB exon 1 deletion (p= 0.01). The two cases from Argentina did not have this haplotype, suggesting that SDHB exon 1 deletion in Argentina have a different origin.

Conclusion

SDHB exon 1 complete deletion was the most frequent SDHB defect in our cohort. Our findings indicate a founder effect for SDHB exon 1 complete deletion in Brazilian patients with paraganglioma.

Support: Sao Paulo Research Foundation (FAPESP) grant 2019/15873-6

Presentation: Saturday, June 11, 2022 1:24 p.m. - 1:29 p.m., Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.

Cytoreductive Surgery of the Primary Tumor in Metastatic Adrenocortical Carcinoma: Impact on Patients' Survival

CONTEXT

The role of cytoreduction of adrenocortical carcinoma (ACC) remains poorly understood.

OBJECTIVE

To analyze the impact of cytoreductive surgery of the primary tumor in patients with metastatic ACC.

DESIGN AND SETTING

We performed a multicentric, retrospective paired cohort study comparing the overall survival (OS) in patients with metastatic ACC who were treated either with cytoreductive surgery (CR group) or without cytoreductive surgery (no-CR group) of the primary tumor. Data were retrieved from 9 referral centers in the American-Australian-Asian Adrenal Alliance collaborative research group.

PATIENTS

Patients aged ≥18 years with metastatic ACC at initial presentation who were treated between January 1, 1995, and May 31, 2019.

INTERVENTION

Performance (or not) of cytoreductive surgery of the primary tumor.

MAIN OUTCOME AND MEASURES

A propensity score match was done using age and the number of organs with metastasis (≤2 or >2). The main outcome was OS, determined from the date of diagnosis until death or until last follow-up for living patients.

RESULTS

Of 339 patients pooled, 239 were paired and included: 128 in the CR group and 111 in the no-CR group. The mean follow-up was 67 months. Patients in the no-CR group had greater risk of death than did patients in the CR group (hazard ratio [HR] = 3.18; 95% CI, 2.34-4.32). Independent predictors of survival included age (HR = 1.02; 95% CI, 1.00-1.03), hormone excess (HR = 2.56; 95% CI, 1.66-3.92), and local metastasis therapy (HR = 0.41; 95% CI, 0.47-0.65).

CONCLUSION

Cytoreductive surgery of the primary tumor in patients with metastatic ACC is associated with prolonged survival.

Genetic and clinical aspects of paediatric pheochromocytomas and paragangliomas

OBJECTIVE

Few and conflicting reports have characterized the genetics of paediatric pheochromocytomas and paragangliomas (PPGLs). This study aimed to investigate the clinical and genetic features of Brazilian children with PPGL.

PATIENTS AND METHODS

This study included 25 children (52% girls) with PPGL. The median age at diagnosis was 15 years (4-19). The median time of follow-up was 145 months. The genetic investigation was performed by Sanger DNA sequencing, multiplex ligation-dependent probe amplification and/or target next-generation sequencing panel.

RESULTS

Of the 25 children with PPGL, 11 (44%), 4 (16%), 2 (8%), 1 (4%) and 7 (28%) had germline VHL pathogenic variants, SDHB, SDHD, RET and negative genetic investigation, respectively. Children with germline VHL missense pathogenic variants were younger than those with SDHB or SDHD genetic defects [median (range), 12 (4-16) vs. 15.5 (14-19) years; P = .027]. Moreover, 10 of 11 cases with VHL pathogenic variants had bilateral pheochromocytoma (six asynchronous and four synchronous). All children with germline SDHB pathogenic variants presented with abdominal paraganglioma (one of them malignant). The two cases with SDHD pathogenic variants presented with head and neck paraganglioma. Among the cases without a genetic diagnosis, 6 and 2 had pheochromocytoma and paraganglioma, respectively. Furthermore, metastatic PPGL was diagnosed in four (16%) of 25 PPGL.

CONCLUSIONS

Most of the paediatric PPGL were hereditary and multifocal. The majority of the affected genes belong to pseudohypoxic cluster 1, with VHL being the most frequently mutated. Therefore, our findings impact surgical management and surveillance of children with PPGL.

Phosphodiesterase 2A and 3B variants are associated with primary aldosteronism

Familial primary aldosteronism (PA) is rare and mostly diagnosed in early-onset hypertension (HT). However, 'sporadic' bilateral adrenal hyperplasia (BAH) is the most frequent cause of PA and remains without genetic etiology in most cases. Our aim was to investigate new genetic defects associated with BAH and PA. We performed whole-exome sequencing (paired blood and adrenal tissue) in six patients with PA caused by BAH that underwent unilateral adrenalectomy. Additionally, we conducted functional studies in adrenal hyperplastic tissue and transfected cells to confirm the pathogenicity of the identified genetic variants. Rare germline variants in phosphodiesterase 2A (PDE2A) and 3B (PDE3B) genes were identified in three patients. The PDE2A heterozygous variant (p.Ile629Val) was identified in a patient with BAH and early-onset HT at 13 years of age. Two PDE3B heterozygous variants (p.Arg217Gln and p.Gly392Val) were identified in patients with BAH and HT diagnosed at 18 and 33 years of age, respectively. A strong PDE2A staining was found in all cases of BAH in zona glomerulosa and/or micronodules (that were also positive for CYP11B2). PKA activity in frozen tissue was significantly higher in BAH from patients harboring PDE2A and PDE3B variants. PDE2A and PDE3B variants significantly reduced protein expression in mutant transfected cells compared to WT. Interestingly, PDE2A and PDE3B variants increased SGK1 and SCNN1G/ENaCg at mRNA or protein levels. In conclusion, PDE2A and PDE3B variants were associated with PA caused by BAH. These novel genetic findings expand the spectrum of genetic etiologies of PA.

MON-218 Clinical and Genetic Aspects of Pediatric Pheochromocytomas and Paragangliomas

Pheochromocytomas and paragangliomas (PPGLs) are neuroendocrine tumors derived from chromaffin cells. At least 30% of PPGL patients have hereditary predisposition. PPGLs in children are more often hereditary, multiple and extra-adrenal. To date, more than 14 tumor-susceptibility genes have been reported: Cluster 1 or hypoxic (VHL, SDHB, SDHD, SDHC, SDHA, SDHAF2, FH, ENGL1 and HIF2A) and cluster 2 (RET, NF1, TMEM127 and MAX). The aim of this study was to evaluate clinical and molecular aspects of a Brazilian cohort of pediatric patients with PPGLs. Out of 262 patients with PPGLs, 26 (9 %) were diagnosed before 19 yrs of age (16 males and 10 females), with a median age of 14.5 yrs (range, 4 to 18). Genetic investigation was performed in 19 patients: 14 by automated Sanger sequencing (VHL, SDHB, SDHD and RET genes) and 5 by a custom next-generation sequencing (NGS) panel including all genes previously associated with germline mutations in PPGLs. Median tumor size was 5.5 cm (1.7 to 16). Pheochromocytomas (PHEOs), paragangliomas (PGLs) or both were diagnosed in 46%, 31% and 23% of the patients, respectively. Bilateral PHEOs were diagnosed in 61% of the cases, most of them asynchronous (75%). Genetic diagnosis was confirmed in 14 out of 19 (74%) patients and all variants were found in heterozygous state: 8 VHL missense mutations from 6 kindreds (p.R167W in 2 kindreds, p.R167Q in one and p.G114S in 3); 3 SDHB mutations (p.C98Y, c.201-2A>G and p.L180L); 2 SDHD mutations (p.Y144_H145del and p.Q121*); and one RET mutation (p.C634R). All 8 VHL patients had bilateral PHEOs and 3 of them had also abdominal PGLs. All patients with SDHB mutations had abdominal PGLs. Two patients with SDHD mutation had head and neck paraganglioma (one of them had unilateral PHEO). Genetic investigation by NGS Panel was negative in all 5 cases: 2 malignant PPGLs (one PHEO and one PGL) and 3 PHEOs. Four out of 26 (15%) pediatric PPGLs were malignant: 2 with SDHB mutation and 2 with negative screening (one PHEO and one PGL). In conclusion, the majority of pediatric PPGLs (74%) were hereditary and almost exclusively caused by mutations in hypoxic genes. VHL (PHEOs) and SDHB (only PGLs) were the most frequent affected genes in this cohort of pediatric PPGLs. Support: CAPES grant to Petenuci J.

MON-206 Diagnosis of Non-Functional Masses in Adrenal Gland Topography - Experience of a Tertiary Health Center

Introduction: Masses in adrenal topography are diagnosed frequently due to the increase in radiological imaging in clinical practice. Adrenal incidentalomas occur between 4% and 10% of the patients above 50 years undergoing abdominal imaging, and the majority are benign pathologies. Objective: To analyze the characteristics of the masses located in adrenal gland topography not originating from the adrenal gland. Methods: We retrospectively assessed patients from our tertiary hospital who underwent surgical treatment for masses in adrenal gland topography between 2006 and 2018. All patients had hormonal evaluations, according to the European and American Societies of Endocrinology guidelines. Two expert radiologists reviewed all images. Forty-six patients were included in the study, and the surgical specimens were analyzed by the same experienced pathologist. Patients with confirmed adrenocortical carcinoma (ACC) were excluded from this cohort. Results: Thirty-two (69.6%) patients were female. The median age was 49.5 years old (range 18-82yo). Abdominal or lumbar pain was the most frequent reason for medical investigation (43.5%). Adrenal incidentalomas represented 38.4% of the cohort. None of these patients had any clinical signs of adrenal hyperfunction, nor hormonal alteration. Twenty-four patients (52.17%) presented a mass on the left side, and only two cases presented bilateral adrenal masses. The median size was 8.6cm (1.3-18cm). The mean of Hounsfield Units (HU) on a non-contrasted CT was 25HU (0-50HU). Several etiologies were found: 8 cases (18%) of ganglioneuroma; 6 cases (13,5%) of adrenal cysts; 4 cases (9%) of leiomyosarcoma and adrenal hemorrhage; 3 cases (6.5%) of infectious disease; 2 cases (4.5%) of lymphangioma, schwannoma, and sarcoma. We also found single cases of renal cell carcinoma, poorly differentiated small cell neuroendocrine carcinoma, hepatocellular carcinoma, high grade dedifferentiated liposarcoma, epithelioid neoplasia, epithelial neoplasia with neuroendocrine differentiation, malignant peripheral nerve sheath tumor of the adrenal gland, poorly differentiated neuroblastoma, high grade lymphoma, myelolipoma, acute splenitis, arteriovenous malformation, and prostate cancer metastasis. Discussion and Conclusion: Ganglioneuroma was the most frequent diagnosis in adrenal incidentalomas in our cohort. In general, these conventional radiological exams could not differentiate lesions originated in the adrenal glands from lesions of other origins. In this large cohort, we could identify non-adrenal origin in approximately 45% of the patients with masses in the adrenal topography.

SAT-560 Usefulness of Contralateral Suppression in Adrenal Venous Sampling to Define Lateralization in Primary Aldosteronism

Primary aldosteronism (PA) is the most common cause of endocrine hypertension. PA subtypes include bilateral hyperplasia and unilateral PA, typically aldosterone-producing adenomas. Adrenal venous (AV) sampling (AVS) is a key step to define PA subtype and guide PA management. According current PA guidelines, most PA patients should undergo AVS, which is a challenging procedure, especially in terms of successfully cannulating the right AV. The aim of this study was to report a single tertiary center experience with AVS in PA patients. We retrospectively evaluated 84 AVS from 1984 to 2019. Sequential AVS was performed by an experienced interventional radiologist. AV and inferior vena cava (IVC) samples were obtained under cosyntropin continuous infusion. Successful catheterization was defined by a selectivity index [SI= AV/IVC cortisol (C) concentrations] ≥5. Unilateral disease was defined by a lateralization index [LI= aldosterone (A)/C ratio in the dominant AV divided by A/C in the non-dominant AV] ≥4. The relative aldosterone secretion index (RASI= A/C ratio in AV divided by A/C in IVC) was calculated in each side. A RASI <1 was defined as contralateral suppression (CS). In patients with unsuccessful AV catheterization (mostly right AV) or undetermined LI (3-4), CS was used to indicate adrenalectomy. The biochemical cure of PA after adrenalectomy was defined as the gold standard parameter to confirm unilateral disease. Successful bilateral AV catheterization was achieved in 75% of the cases. After 2015, the use of intra-procedural rapid cortisol assay improved angiographer experience and increased AVS successful rate from 52 to 80%. LI revealed unilateral and bilateral aldosterone excess in 68 and 32% of the cases, respectively. A LI ≥4 had a sensitivity of 100% and specificity of 98% to define unilateral PA among patients with successful catheterization. In addition, RASI in the non-dominant AV was significantly lower in unilateral PA according the LI when compared to bilateral cases [0.12 (0.03 to 1.18) vs. 1.1 (0.04 to 4.56), p= 0.0001]. RASI in the non-dominant AV was inversely correlated with LI (r= -0.81, p= 0.0001). A CS index ≤0.5 had a high sensitivity (90%) and specificity (94%) to define unilateral aldosterone excess. In conclusion, the LI is the most valuable parameter in AVS for PA subtyping. Additionally, CS (cut-off of 0.5) is very useful to define lateralization and can be used in cases of borderline LI or unsuccessful AV catheterization.CAPES Grant to Freitas TC.

SUN-178 Clinical and Anatomopathological Characteristics of Two Atypical Aldosterone-Producing Adenomas

Background: Aldosterone producing adenomas (APAs) are the most common cause of unilateral primary aldosteronism (PA). In most cases, APAs present as small (<2 cm in diameter) benign appearing nodules on computed tomography (CT). Up to 70% of APAs may harbor KCNJ5 somatic mutations.

Clinical Cases: Case 1. A 33-yr-old man was referred to investigate resistant hypertension (HT). Biochemical evaluation revealed normal K levels, aldosterone (A) of 14.7 ng/dl, renin of 2.1 mUI/L (normal, 4.4-46.1) and A/R ratio of 24.8. Confirmatory testing confirmed PA diagnosis. Hypercortisolism investigation revealed a non-suppressible cortisol after an overnight 1 mg low-dose dexamethasone suppression (8.3 μg/dL), abnormal midnight salivary cortisol, and normal urinary free cortisol, plasma DHEAS and ACTH levels. Computed tomography (CT) scan showed a well-limited mass in left adrenal, measuring 5.8 cm with pre-contrast density of 30 HU and absolute wash-out of 72%. After left laparoscopic adrenalectomy, hydrocortisone was started and adrenal insufficiency confirmed by basal cortisol <3 μg/dL. He presented biochemical cure of PA and improvement in HT control. Histologic examination revealed an encapsulated tumor with glomerulosa-like cells predominance and a Weiss score 1 (clear cells <25%). CYP11B2 staining was positive in 10% and Ki67 in 5% of tumor cells. Case 2. A 58 yr-old woman was referred to investigate an adrenal mass. She had resistant HT and hypokalemia since 2010. Biochemical evaluation revealed hypokalemia (2.8 mEq/L), A of 16.9 ng/dl, renin <1.6 mUI/L and A/R ratio of 10.6. Confirmatory testing confirmed PA diagnosis. Hypercortisolism investigation was negative. CT scan showed a heterogeneous solid mass in the right adrenal, measuring 5.5 cm with pre-contrast density of 30 HU and absolute wash-out of 77%. After laparoscopic right adrenalectomy, histologic examination revealed an encapsulated tumor with glomerulosa-like cells predominance and a Weiss score 2 (clear cells < 25% and > 1/3 diffuse architecture). CYP11B2 staining was positive in 30% and Ki67 in 5% of the cells. She presented biochemical cure of PA and improvement in HT control. Genetic investigation for somatic KCNJ5, ATP1A1, ATP2B3 and CTNNB1 was negative in both cases.

Conclusion: We describe two rare cases of APAs that presented as large and suspicious tumors, without somatic mutations in genes associated with APAs.

SUN-218 Analysis of ATRX and ZNRF3 Expression and Copy Number Variation in a Pediatric and Adult Cohort with Adrenocortical Tumors

Introduction: Adrenocortical carcinoma (ACC) is a rare malignancy with an incidence of 1 to 2 cases per million/year in adults and with a global survival rate of less than 40% in 5 years. ACC diagnosis was based on Weiss criteria for adult patients. Pediatric patients with adrenocortical tumors (PAT), in general, are associated with better survival in most cases, and the malignant disease is established when local or distant metastases are found. The integrated and extensive genomic-molecular characterization of ACC has resulted in a better understanding of its pathophysiology. Some studies have demonstrated the involvement of ATRX and ZNRF3 genes in adrenal tumorigenesis in pediatric and adult patients with PAT and ACC, respectively. However, these data have not been validated in a Brazilian cohort with a high prevalence of the TP53 germline R337H mutation. Objectives: We aimed to evaluate the ATRX and ZNRF3 expression and copy number variation in a Brazilian cohort of patients with PAT and adults with ACC from a tertiary center. Patients and Methods: 34 adults (19 women - 56%) with median age 49 years old (range 18-83) and twelve pediatric patients (7 girls - 58%) with median age three years old (0.8-15 years old) were included in this study. The epidemiological data, clinical presentation, hormonal data, radiological imaging, and genetic background for TP53 were retrospectively evaluated. MLPA and RT-PCR were employed to evaluate the copy number variation and the gene expression, respectively, of ATRX and ZNRF3 in tumor tissues. Results: Adult group: Seven patients out of 27 (25.9%) presented the pathogenic germline mutation pR337H onTP53. 20 patients (58.8%) presented metastasis, and 19 (55%) had a fatal outcome. The median global survival was 17.23 months (0.6-185.8 m). Pediatric group: 10 patients (83.3%) presented the pathogenic germline mutation p.R337H on TP53. Four patients presented metastasis and only two had a fatal outcome. The median global survival was 42.4months (6.63-125.5m). All tumors were functional. Molecular results: Three out of 33 adult patients (9%), and 2 out of 12 (16.6%) pediatric patients presented deletion on ATRX. Four out of 25 adults (16%) and 2 out of 12 pediatric (16.6%) patients showed deletion on ZNRF3. There was no correlation between ATRX and ZNRF3 expressions or deletions with the overall survival rate (p&gt;0.05). The decrease in the ATRX expression was associated with the presence of TP53 germline mutation in pediatric and adult cohorts (p 0.028). Conclusion: We confirmed the presence of alterations on ATRX and ZNRF3 genes in both cohort (adult and pediatric tumors). These results differ from the previous studies, which demonstrated ATRX and ZNRF3 alterations were present in pediatric and adult tumors, respectively. However, prospective studies with larger cohorts are necessary to confirm the prognostic value of ATRX and ZNRF3 genes in PAT and adults with ACC.

Internal validation and decision curve analysis of a preoperative nomogram predicting a postoperative complication in pheochromocytoma surgery: An international study

OBJECTIVES

To develop a preoperative nomogram that would predict the risk of a postoperative complication for pheochromocytoma patients undergoing adrenalectomy using an international database.

METHODS

We retrospectively analyzed preoperative variables and postoperative outcomes in patients who underwent adrenalectomy for pheochromocytoma in three institutions from 2000 to 2017. Internal validation of a generated nomogram was carried out with receiver operating characteristics, calibration plots, and decision curve analyses.

RESULTS

A total of 153 patients who had undergone 166 adrenalectomies were included in the study. Overall, post-adrenalectomy complications were seen in 30% of patients, whereas 9.6% of patients sustained a Clavien ≥3a complication. Independent predictors of a complication were a history of hypertension, body mass index, tumor size, and Charlson Comorbidity Index score. On internal validation, the multivariable model generated a nomogram that predicted a postoperative complication or clinically hemodynamic event with an area under the curve of 0.86, showed good calibration and had an overall net benefit.

CONCLUSIONS

An internally validated nomogram combining body mass index, Charlson Comorbidity Index score and tumor size can predict the probability of a post-adrenalectomy complication in those with and without hypertension. The model, the first of its kind in pheochromocytoma surgery, identifies patients at risk of a postoperative complication at the time of their presentation with pheochromocytoma.

Perioperative outcomes of laparoscopic, robotic, and open approaches to pheochromocytoma

While multiple studies have demonstrated that minimally invasive surgical (MIS) techniques are a safe and efficacious approach to adrenalectomy for pheochromocytomas (PC), these studies have only been small comparative studies. The aim of this multi-institutional study is to compare perioperative outcomes between open and MIS, stratified by robotic and conventional laparoscopic, techniques in the surgical management of PC. We retrospectively evaluated patients who underwent adrenalectomy for PCs from 2000 to 2017 at three different institutions. Clinical, perioperative, and pathologic parameters were analyzed using t test, Chi square, and Fisher exact statistical measures. Of the 156 adrenalectomy cases performed, 26 (16.7%) were with an open approach and 130 (83.3%) using MIS techniques. Of the MIS procedures, 41 (31.5%) were performed robotically and 89 (68.5%) performed laparoscopically without robotic assistance. Demographic and clinical parameters were similar between the open and MIS groups. Patients, who underwent MIS procedure had a lower complication rate (p = 0.04), shorter hospitalization (p = 0.02), shorter operative time (p < 0.001), and less blood loss (p = 0.002) than those who underwent open surgical resection. Conventional laparoscopic and robotic operative approaches resulted in similar complication rates, length of hospitalization, and blood loss. Our study is one of the largest cohorts comparing the perioperative outcomes between conventional laparoscopic and robotic adrenalectomies in patients with PC. Our results support that MIS techniques have potentially lower morbidity compared to open techniques, while laparoscopic and robotic approaches have similar perioperative outcomes.

KCNJ5 Somatic Mutation Is a Predictor of Hypertension Remission After Adrenalectomy for Unilateral Primary Aldosteronism

CONTEXT

Primary aldosteronism (PA) is the most common cause of endocrine hypertension (HT). HT remission (defined as blood pressure <140/90 mm Hg without antihypertensive drugs) has been reported in approximately 50% of patients with unilateral PA after adrenalectomy. HT duration and severity are predictors of blood pressure response, but the prognostic role of somatic KCNJ5 mutations is unclear.

OBJECTIVE

To determine clinical and molecular features associated with HT remission after adrenalectomy in patients with unilateral PA.

METHODS

We retrospectively evaluated 100 patients with PA (60 women; median age at diagnosis 48 years with a median follow-up of 26 months). Anatomopathological analysis revealed 90 aldosterone-producing adenomas, 1 carcinoma, and 9 unilateral adrenal hyperplasias. All patients had biochemical cure after unilateral adrenalectomy. KCNJ5 gene was sequenced in 76 cases.

RESULTS

KCNJ5 mutations were identified in 33 of 76 (43.4%) tumors: p.Gly151Arg (n = 17), p.Leu168Arg (n = 15), and p.Glu145Gln (n = 1). HT remission was reported in 37 of 100 (37%) patients. Among patients with HT remission, 73% were women (P = 0.04), 48.6% used more than three antihypertensive medications (P = 0.0001), and 64.9% had HT duration <10 years (P = 0.0015) compared with those without HT remission. Somatic KCNJ5 mutations were associated with female sex (P = 0.004), larger nodules (P = 0.001), and HT remission (P = 0.0001). In multivariate analysis, only a somatic KCNJ5 mutation was an independent predictor of HT remission after adrenalectomy (P = 0.004).

CONCLUSION

The presence of a KCNJ5 somatic mutation is an independent predictor of HT remission after unilateral adrenalectomy in patients with unilateral PA.

Presentation and surgery outcomes in elderly with pheocromocytoma: a comparative analysis with Young patients

Purpose:

To evaluate the presentation and early surgical outcomes of elderly patients undergoing adrenalectomy for phaeochromocytoma.

Patients and Methods:

A retrospective search was performed of our adrenal disorders database for patients who underwent surgery for phaeochromocytoma or paraganglioma between 2009 and 2014. Patients >60 years old were classified as elderly. The clinical manifestations, intraoperative course, and early postoperative outcomes of elderly patients were compared to those of younger individuals (<60 years old).

Results:

The mean (±standard deviation) age in the older (n=10) and younger (n=36) groups was 69.6±5.3 years and 34.0±12.9 years. Germ-line mutations were more common in younger patients (50.0% versus 0%; p=0.004), whereas incidental lesions were more common in the elderly (40.0% versus 5.3%; p=0.003). In both groups, surgery was most commonly performed by videolaparoscopy (90% in the elderly and 82% in the younger group), with similar intraoperative anesthetic and surgical outcomes. Postoperatively, the older group more commonly received vasoactive drugs (60.0% versus 10.5%; p<0.001) and had a longer intensive care unit stay (3.1±2.8 versus 1.4±1.0 days; p=0.014), more clinical complications (60% versus 18.9%; p=0.01), and longer hospital stay (10.2±8.4 versus 5.7±4.9 days; p=0.028).

Conclusions:

Although all patients received the same preoperative preparation, the elderly group exhibited a slower and more complicated recovery after adrenalectomy. Meticulous perioperative care should be used in the elderly when treating phaeochromocytoma; nevertheless, adrenalectomy is a relatively safe procedure in this patient population.