PCDHGC3 hypermethylation as a potential biomarker of intestinal neuroendocrine carcinomas

Neuroendocrine neoplasms (NENs) encompass tumors arising from neuroendocrine cells in various organs, including the gastrointestinal tract, pancreas, adrenal gland, and paraganglia. Despite advancements, accurately predicting the aggressiveness of gastroenteropancreatic (GEP) NENs based solely on pathological data remains challenging, thereby limiting optimal clinical management. Our previous research unveiled a crucial link between hypermethylation of the protocadherin PCDHGC3 gene and neuroendocrine tumors originating from the paraganglia and adrenal medulla. This epigenetic alteration was associated with increased metastatic potential and succinate dehydrogenase complex (SDH) dysfunction. Expanding upon this discovery, the current study explored PCDHGC3 gene methylation within the context of GEP-NENs in a cohort comprising 34 cases. We uncovered promoter hypermethylation of PCDHGC3 in 29% of GEP-NENs, with a significantly higher prevalence in gastrointestinal (GI) neuroendocrine carcinomas (NECs) compared with both pancreatic (Pan) NECs and neuroendocrine tumors (NETs) of GI and Pan origin. Importantly, these findings were validated in one of the largest multi-center GEP-NEN cohorts. Mechanistic analysis revealed that PCDHGC3 hypermethylation was not associated with SDH mutations or protein loss, indicating an SDH-independent epigenetic mechanism. Clinically, PCDHGC3 hypermethylation emerged as a significant prognostic factor, correlating with reduced overall survival rates in both patient cohorts. Significantly, whereas PCDHGC3 hypermethylation exhibited a strong correlation with TP53 somatic mutations, a hallmark of NEC, its predictive value surpassed that of TP53 mutations, with an area under the curve (AUC) of 0.95 (95% CI 0.83-1.0) for discriminating GI-NECs from GI-NETs, highlighting its superior predictive performance. In conclusion, our findings position PCDHGC3 methylation status as a promising molecular biomarker for effectively stratifying patients with GI-NENs. This discovery has the potential to advance patient care by enabling more precise risk assessments and tailored treatment strategies. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Risk factors for intraoperative hypertensive crisis in patients with pheochromocytomas and sympathetic paragangliomas

PURPOSE

To identify presurgical and surgical risk factors for intraoperative hypertensive crisis in patients with pheochromocytomas and sympathetic paragangliomas (PGLs) (PPGLs).

METHODS

Retrospective multicenter cohort study of patients with PPGLs from 18 tertiary hospitals. Intraoperative hypertensive crisis was defined as systolic blood pressure (SBP) greater than 200 mmHg lasting more than 1 min and postoperative hypertensive crisis as SBP greater than 180 mmHg or diastolic blood pressure (DBP) greater than 110 mmHg.

RESULTS

A total of 296 surgeries were included. Alpha presurgical blockade was employed in 93.2% of the cases and beta-adrenergic in 53.4%. Hypertensive crisis occurred in 20.3% ( n  = 60) of the surgeries: intraoperative crisis in 56 and postoperative crisis in 6 cases (2 cases had both types of crises). We identified as risk factors of intraoperative hypertensive crisis, absence of presurgical glucocorticoid therapy (odds ratio [OR] 3.48; 95% confidence interval [CI] 1.19-10.12) higher presurgical SBP (OR 1.22 per each 10 mmHg, 95% CI 1.03-1.45), a larger tumor size (OR 1.09 per each 10 mm, 95% CI 1.00-1.19) and absence of oral sodium repletion (OR 2.59, 95% CI 1.25-5.35). Patients with hypertensive crisis had a higher rate of intraoperative bleeding ( P  < 0.001), of intraoperative hemodynamic instability ( P  < 0.001) and of intraoperative hypotensive episodes ( P  < 0.001) than those without hypertensive crisis.

CONCLUSION

Intraoperative hypertensive crisis occurs in up to 20% of the PPGL resections. Patients not pretreated with glucocorticoid therapy before surgery, with larger tumors and higher presurgical SBP and who do not receive oral sodium repletion have a higher risk for developing hypertensive crisis during and after PPGL surgery.

Local recurrence and metastatic disease in pheochromocytomas and sympathetic paragangliomas

Purpose

To evaluate the rate of recurrence among patients with pheochromocytomas and sympathetic paragangliomas (PGLs; together PPGLs) and to identify predictors of recurrence (local recurrence and/or metastatic disease).

Methods

This retrospective multicenter study included information of 303 patients with PPGLs in follow-up in 19 Spanish tertiary hospitals. Recurrent disease was defined by the development of local recurrence and/or metastatic disease after initial complete surgical resection.

Results

A total of 303 patients with PPGLs that underwent 311 resections were included (288 pheochromocytomas and 15 sympathetic PGLs). After a median follow-up of 4.8 years (range 1-19), 24 patients (7.9%) had recurrent disease (3 local recurrence, 17 metastatic disease and 4 local recurrence followed by metastatic disease). The median time from the diagnosis of the PPGL to the recurrence was of 11.2 months (range 0.5-174) and recurrent disease cases distributed uniformly during the follow-up period. The presence of a pathogenic variant in SDHB gene (hazard ratio [HR] 13.3, 95% CI 4.20-41.92), higher urinary normetanephrine levels (HR 1.02 per each increase in standard deviation, 95% CI 1.01-1.03) and a larger tumor size (HR 1.01 per each increase in mm, 95% CI 1.00-1.02) were independently associated with disease recurrence.

Conclusion

The recurrence of PPGLs occurred more frequently in patients with SDHB mutations, with larger tumors and with higher urinary normetanephrine levels. Since PPGL recurrence may occur at any time after the initial PPGL diagnosis is performed, we recommend performing a strict follow-up in all patients with PPGLs, especially in those patients with a higher risk of recurrent disease.

Assessment of obesity stigma and discrimination among Spanish subjects with a wide weight range: the OBESTIGMA study

Introduction

This study aims to assess the extent of rejection and instances of stigmatization linked to obesity within the Spanish population, encompassing a diverse spectrum of weights ranging from normal weight to morbid obesity. Additionally, the study seeks to identify the primary factors influencing these experiences and further examines the impact of bariatric surgery on such dynamics.

Materials and methods

Multicenter observational study with involving a total of 1,018 participants who were recruited from various Obesity Units. Negatives attitudes towards people with obesity were assessed through three questionnaires: (i) Antifat Attitudes Scale (AFA), (ii) Stigmatizing Situations Inventory (SSI) and (iii) Weight Bias Internalization Scale (WBIS). Subjects were categorized into four groups based on their BMI and history of prior bariatric surgery.

Results

The cumulative score across all questionnaires (AFA, SSI and WBIS) exhibited a progressive increase, from participants with normal weight to those with obesity (p < 0.001 for all). Within the AFA questionnaire, males showed more rejection towards people with obesity than women, also perceiving obesity as a disease linked to a lack of willpower (p = 0.004 and p = 0.030, respectively). The overall SSI score was negatively associated with age (r = -0.080, p = 0.011), with young participants encountering more stigmatizing experiences than their adult counterparts. Neither employment status nor educational demonstrated a significant association with any of the questionnaires. Interestingly, patients who underwent lost weight following bariatric surgery did not exhibit improved outcomes.

Conclusion

Individuals with obesity demonstrate a heightened level of aversion towards the disease compared to those with normal weight. Concurrently, the incidence of stigmatizing encounters displays a concerning escalation among younger individuals.

An Integrated CT and MRI Imaging Model to Differentiate between Adrenal Adenomas and Pheochromocytomas

PURPOSE

to perform an external validation of our predictive model to rule out pheochromocytoma (PHEO) based on unenhanced CT in a cohort of patients with PHEOs and adenomas who underwent adrenalectomy.

METHODS

The predictive model was previously developed in a retrospective cohort of 1131 patients presenting with adrenal lesions. In the present study, we performed an external validation of the model in another cohort of 214 patients with available histopathological results.

RESULTS

For the external validation, 115 patients with PHEOs and 99 with adenomas were included. Our previously described predictive model combining the variables of high lipid content and tumor size in unenhanced CT (AUC-ROC: 0.961) had a lower diagnostic accuracy in our current study population for the prediction of PHEO (AUC: 0.750). However, when we excluded atypical adenomas (with Hounsfield units (HU) > 10, n = 39), the diagnostic accuracy increased to 87.4%. In addition, in the whole cohort (including atypical adenomas), when MRI information was included in the model, the diagnostic accuracy increased to up to 85% when the variables tumor size, high lipid content in an unenhanced CT scan, and hyperintensity in the T2 sequence in MRI were included. The probability of PHEO was <0.3% for adrenal lesions <20 mm with >10 HU and without hyperintensity in T2.

CONCLUSION

Our study confirms that our predictive model combining tumor size and lipid content has high reliability for the prediction of PHEO when atypical adrenal lesions are excluded. However, for atypical adrenal lesions with >10 HU in an unenhanced CT scan, MRI information is necessary for a proper exclusion of the PHEO diagnosis.

Visual analytics identifies key miRNAs for differentiating peripancreatic paraganglioma and pancreatic neuroendocrine tumors

Introduction

Paragangliomas (PGL), a type of neuroendocrine tumor, pose a significant diagnostic challenge due to their potential for unpredictable locations and asymptomatic presentation. Misdiagnosis of peripancreatic PGLs, particularly as pancreatic neuroendocrine tumors (PANNETs), is a pressing issue as it can negatively impact both pre- and post-treatment decision-making. The aim of our study was to identify microRNA markers for the reliable differential diagnosis of peripancreatic PGLs and PANNETs, addressing a crucial unmet need in the field and advancing the standard of care for these patients.

Methods

Morphing projections tool was used to analyze miRNA data from PGL and PANNET tumors present in the TCGA database. The findings were validated using two additional databases: GSE29742 and GSE73367.

Results

Our research uncovered substantial differences in the miRNA expression profiles of PGL and PANNET, leading to the identification of 6 key miRNAs (miR-10b-3p, miR-10b-5p, and the miRNA families miR-200c/141 and miR-194/192) that can effectively differentiate between the two types of tumors.

Discussion

These miRNA levels hold potential as biomarkers for improved diagnosis, offering a solution to the diagnostic challenge posed by these tumors and potentially improving the standard of care for patients.

Differences in intraoperative and surgical outcomes between normotensive pheochromocytomas and sympathetic paragangliomas (PPGLs) and hypertensive PPGLs: results from the PHEO-RISK STUDY

PURPOSE

To compare the intraoperative and surgical outcomes of normotensive pheochromocytomas and sympathetic paragangliomas (PPGLs), hypertensive PPGLs and non-PPGL adrenal lesions.

METHODS

This a retrospective multicenter cohort study of patients with PPGLs from 18 tertiary hospitals. A control group of histologically confirmed adrenocortical adenomas (non-PPGL group) was selected to compare intraoperative and surgical outcomes with of the normotensive PPGLs.

RESULTS

Two hundred and ninety-six surgeries performed in 289 patients with PPGLs were included. Before surgery, 209 patients were classified as hypertensive PPGLs (70.6%) and 87 as normotensive PPGLs. A higher proportion of normotensive PPGLs than hypertensive PPGLs did not receive alpha presurgical blockade (P = 0.009). When we only considered those patients who received presurgical alpha blockers (200 hypertensive PPGLs and 76 normotensive PPGLs), hypertensive PPGLs had a threefold higher risk of intraoperative hypertensive crisis (OR 3.0 [95% 1.3-7.0]) and of hypotensive episodes (OR 2.9 [95% CI 1.2-6.7]) than normotensive PPGLs. When we compared normotensive PPGLs (n = 76) and non-PPGLs (n = 58), normotensive PPGLs had a fivefold higher risk of intraoperative complications (OR 5.3 [95% CI 1.9-14.9]) and a six times higher risk of postoperative complications (OR 6.1 [95% CI 1.7-21.6]) than non-PPGLs.

CONCLUSION

Although the risk of intraoperative hypertensive and hypotensive episodes in normotensive PPGLs is significantly lower than in hypertensive PPGLs, normotensive PPGLs have a greater risk of intraoperative and postoperative complications than non-PPGL adrenal lesions. Therefore, it is recommended to follow the standard of care for presurgical and anesthetic management of PPGLs also in normotensive PPGLs.

Genetic study in pheochromocytoma ¿is it possible to stratify the risk of hereditary pheochromocytoma?

INTRODUCTION

It is estimated that 30-40% of patients with apparently sporadic pheochromocytomas (PHEOs) have an inherited predisposition syndrome. The aim of our study was to develop a predictive model of hereditary pheochromocytoma (PHEO) based on the clinical, hormonal, and radiological features present at the diagnosis of patients with PHEOs.

METHODS

A retrospective multicenter cohort study of patients with PHEOs with available genetic study from 18 tertiary hospitals. Clinical, biochemical, and radiological features were used to build a multivariate logistic regression model. The estimation of all possible equations was used to select the model with the best diagnostic accuracy (lower Akaike index (AIC)).

RESULTS

A total of 245 patients were included: 169 (69.0%) patients with sporadic PHEOs and 76 (31%) with hereditary PHEOs. The parsimonious predictive model with the highest diagnostic accuracy for the prediction of hereditary PHEO combined the variables age, non-cardiovascular disease, urinary norepinephrine levels and tumor size. The area under the ROC curve of this model was of 0.800 (0.705-0.887). Based on the predictive model, the probability of hereditary PHEO in patients older than 60 years with cardiovascular disease, high levels of urinary norepinephrine and unilateral PHEOs >60 mm was <2%. And if the age was above 80 years, lower than 1%. The probability of sporadic PHEO linearly increased with age (MH Test for linear Trend: Chi2(1) = 30.05; P<0.001) Conclusion: In certain populations such as old patients with cardiovascular disease, with high levels of urinary norepinephrine and large tumors in which the probability of hereditary PHEO is very low, genetic testing could be avoided in the absence of specific suspicion.

Exploratory Analysis of the Gene Expression Matrix Based on Dual Conditional Dimensionality Reduction

One of the major goals in gene expression data analysis is to explore and discover groups of genes and groups of biological conditions with meaningful relationships. While this problem can be addressed by algorithms, their results require an analysis within context, since they may be affected by many side processes -such as tissue differentiation- that could hinder the target goal. Visual analytics-based methods for exploratory analysis of the gene expression matrix (GEM) are essential in biomedical research since they allow us to frame the analysis within the user's knowledge domain. In this paper, we present a visual analytics approach to discover relevant connections between genes and samples based on linking a reordered GEM heatmap and dual 2D projections of its rows and columns, which can be recomputed conditioned by subsets of genes and/or samples selected by the user during the analysis. We demonstrate the capability of our approach to discover relevant knowledge in three case studies involving two cancer types plus normal tissue from the TCGA database.

Pseudohypoxia in paraganglioma and pheochromocytoma is associated with an immunosuppressive phenotype

Metastatic pheochromocytoma and paraganglioma (PPGL) have poor prognosis and limited therapeutic options. The recent advent of immunotherapies showing remarkable clinical efficacies against various cancer types offers the possibility of novel opportunities also for metastatic PPGL. Most PPGLs are pathogenically linked to inactivating mutations in genes encoding different succinate dehydrogenase (SDH) subunits. This causes activation of the hypoxia-inducible factor 2 (HIF2)-mediated transcriptional program in the absence of decreased intratumoral oxygen levels, a phenomenon known as pseudohypoxia. Genuine hypoxia in a tumor creates an immunosuppressive tumor microenvironment. However, the impact of pseudohypoxia in the immune landscape of tumors remains largely unexplored. In this study, tumoral expression of programmed death-ligand 1 (PD-L1) and HIF2α and tumor infiltration of CD8 T lymphocytes (CTLs) were examined in PPGL specimens from 102 patients. We assessed associations between PD-L1, CTL infiltration, HIF2α expression, and the mutational status of SDH genes. Our results show that high PD-L1 expression levels in tumor cells and CTL tumor infiltration were more frequent in metastatic than nonmetastatic PPGL. However, this phenotype was negatively associated with SDH mutations and high HIF2α protein expression. These data were validated by analysis of mRNA levels of genes expressing PD-L1, CD8, and HIF2α in PPGL included in The Cancer Genome Atlas database. Further, PD-L1 and CD8 expression was lower in norepinephrine than epinephrine-secreting PPGL. This in silico analysis also revealed the low PD-L1 or CD8 expression levels in tumors with inactivating mutations in VHL or activating mutations in the HIF2α-coding gene, EPAS1, which, together with SDH-mutated tumors, comprise the pseudohypoxic molecular subtype of PPGL. These findings suggest that pseudohypoxic tumor cells induce extrinsic signaling toward the immune cells promoting the development of an immunosuppressive environment. It also provides compelling support to explore the differential response of metastatic PPGL to immune checkpoint inhibitors. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Glycemic disorders in patients with pheochromocytomas and sympathetic paragangliomas

The objective of our study was to determine the prevalence of glycemic disorders (diabetes mellitus and prediabetes) in patients with pheochromocytomas and sympathetic paragangliomas (PPGLs) and identify risk factors for their development and the likelihood of their resolution after surgery. A multicentric retrospective study of patients with PPGLs submitted to surgery between 2000 and 2021 in 17 Spanish hospitals was performed. Diabetes-specific data were collected at diagnosis, in the immediate- and long-term postsurgical follow-up. A total of 229 patients with PPGLs were included (218 with pheochromocytomas and 11 with sympathetic paragangliomas). Before surgery, glycemic disorders were diagnosed in 35.4% of the patients (n = 81): 54 with diabetes and 27 with prediabetes. The variables independently associated with a higher risk of glycemic disorders were sporadic PPGL (odds ratio (OR) = 3.26 (1.14-9.36)) and hypertension (OR = 3.14 (1.09-9.01)). A significant decrease in fasting plasma glucose and HbA1c levels was observed after surgery, in the short-term and long-term follow-up (P < 0.001). After a median follow-up of 48.5 months (range 3.3-168.9), after surgery, 52% of diabetic and 68% of prediabetic patients experienced a complete resolution. Lower body mass index (BMI) (P = 0.001), lower glucose levels (P = 0.047) and shorter duration of diabetes prior to surgery (P = 0.021) were associated with a higher probability of diabetes resolution. In conclusion, glycemic disorders in patients with PPGLs are present in more than a third of them at diagnosis. Sporadic PPGLs and hypertension are risk factors for their development. More than 50% of cases experience a complete resolution of the glycemic disorder after resection of the PPGLs.

Age-dependent and sex-dependent disparity in mortality in patients with adrenal incidentalomas and autonomous cortisol secretion: an international, retrospective, cohort study

BACKGROUND

The association between cortisol secretion and mortality in patients with adrenal incidentalomas is controversial. We aimed to assess all-cause mortality, prevalence of comorbidities, and occurrence of cardiovascular events in uniformly stratified patients with adrenal incidentalomas and cortisol autonomy (defined as non-suppressible serum cortisol on dexamethasone suppression testing).

METHODS

We conducted an international, retrospective, cohort study (NAPACA Outcome) at 30 centres in 16 countries. Eligible patients were aged 18 years or older with an adrenal incidentaloma (diameter ≥1 cm) detected between Jan 1, 1996, and Dec 31, 2015, and availability of a 1 mg dexamethasone suppression test result from the time of the initial diagnosis. Patients with clinically apparent hormone excess, active malignancy, or follow-up of less than 36 months were excluded. Patients were stratified according to the 0800-0900 h serum cortisol values after an overnight 1 mg dexamethasone suppression test; less than 50 nmol/L was classed as non-functioning adenoma, 50-138 nmol/L as possible autonomous cortisol secretion, and greater than 138 nmol/L as autonomous cortisol secretion. The primary endpoint was all-cause mortality. Secondary endpoints were the prevalence of cardiometabolic comorbidities, cardiovascular events, and cause-specific mortality. The primary and secondary endpoints were assessed in all study participants.

FINDINGS

Of 4374 potentially eligible patients, 3656 (2089 [57·1%] with non-functioning adenoma, 1320 [36·1%] with possible autonomous cortisol secretion, and 247 [6·8%] with autonomous cortisol secretion) were included in the study cohort for mortality analysis (2350 [64·3%] women and 1306 [35·7%] men; median age 61 years [IQR 53-68]; median follow-up 7·0 years [IQR 4·7-10·2]). During follow-up, 352 (9·6%) patients died. All-cause mortality (adjusted for age, sex, comorbidities, and previous cardiovascular events) was significantly increased in patients with possible autonomous cortisol secretion (HR 1·52, 95% CI 1·19-1·94) and autonomous cortisol secretion (1·77, 1·20-2·62) compared with patients with non-functioning adenoma. In women younger than 65 years, autonomous cortisol secretion was associated with higher all-cause mortality than non-functioning adenoma (HR 4·39, 95% CI 1·93-9·96), although this was not observed in men. Cardiometabolic comorbidities were significantly less frequent with non-functioning adenoma than with possible autonomous cortisol secretion and autonomous cortisol secretion (hypertension occurred in 1186 [58·6%] of 2024 patients with non-functioning adenoma, 944 [74·0%] of 1275 with possible autonomous cortisol secretion, and 179 [75·2%] of 238 with autonomous cortisol secretion; dyslipidaemia occurred in 724 [36·2%] of 1999 patients, 547 [43·8%] of 1250, and 123 [51·9%] of 237; and any diabetes occurred in 365 [18·2%] of 2002, 288 [23·0%] of 1250, and 62 [26·7%] of 232; all p values <0·001).

INTERPRETATION

Cortisol autonomy is associated with increased all-cause mortality, particularly in women younger than 65 years. However, until results from randomised interventional trials are available, a conservative therapeutic approach seems to be justified in most patients with adrenal incidentaloma.

FUNDING

Deutsche Forschungsgemeinschaft, Associazione Italiana per la Ricerca sul Cancro, Università di Torino.

Risk factors for intraoperative complications in pheochromocytomas

We aimed to identify presurgical and surgical risk factors for intraoperative complications in patients with pheochromocytomas. A retrospective study of patients with pheochromocytomas who underwent surgery in ten Spanish hospitals between 2011 and 2021 was performed. One hundred and sixty-two surgeries performed in 159 patients were included. The mean age was 51.6 ± 16.4 years old and 52.8% were women. Median tumour size was 40 mm (range 10-110). Laparoscopic adrenalectomy was performed in 148 patients and open adrenalectomy in 14 patients. Presurgical alpha- and beta-blockade was performed in 95.1% and 51.9% of the surgeries, respectively. 33.3% of the patients (n = 54) had one or more intraoperative complications. The most common complication was the hypertensive crisis in 21.0%, followed by prolonged hypotension in 20.0%, and hemodynamic instability in 10.5%. Patients pre-treated with doxazosin required intraoperative hypotensive treatment more commonly than patients pre-treated with other antihypertensive drugs (51.1% vs 26.5%, P = 0.002). Intraoperative complications were more common in patients with higher levels of urine metanephrine (OR = 1.01 for each 100 μg/24 h, P = 0.026) and normetanephrine (OR = 1.00 for each 100 μg/24 h, P = 0.025), larger tumours (OR = 1.4 for each 10 mm, P < 0.001), presurgical blood pressure > 130/80 mmHg (OR = 2.25, P = 0.027), pre-treated with doxazosin (OR = 2.20, P = 0.023) and who had not received perioperative hydrocortisone (OR = 3.95, P = 0.008). In conclusion, intraoperative complications in pheochromocytoma surgery are common and can be potentially life-threatening. Higher metanephrine and normetanephrine levels, larger tumour size, insufficient blood pressure control before surgery, pre-treatment with doxazosin, and the lack of treatment with perioperative hydrocortisone are associated with higher risk of intraoperative complications.

Clinical and genetic characteristics in patients under 30 years with sporadic pituitary adenomas

OBJECTIVE

Pituitary adenomas (PA) are rare in young patients, and additional studies are needed to fully understand their pathogenesis in this population. We describe the clinical and genetic characteristics of apparently sporadic PA in a cohort of young patients.

DESIGN

Clinical and molecular analysis of 235 patients (age ≤ 30 years) with PA. Clinicians from several Spanish and Chilean hospitals provided data.

METHODS

Genetic screening was performed via next-generation sequencing and comparative genomic hybridization array. Clinical variables were compared among paediatric, adolescent (<19 years) and young adults' (≥19-30 years) cohorts and types of adenomas. Phenotype-genotype associations were examined.

RESULTS

Among the total cohort, mean age was 17.3 years. Local mass effect symptoms were present in 22.0%, and prolactinomas were the most frequent (44.7%). Disease-causing germline variants were identified in 22 individuals (9.3%), more exactly in 13.1 and 4.7% of the populations aged between 0-19 and 19-30 years, respectively; genetically positive patients were younger at diagnosis and had larger tumour size. Healthy family carriers were also identified.

CONCLUSIONS

Variants in genes associated with syndromic forms of PAs were detected in a large cohort of apparently sporadic pituitary tumours. We have identified novel variants in well-known genes and set the possibility of incomplete disease penetrance in carriers of MEN1 alterations or a limited clinical expression of the syndrome. Despite the low penetrance observed, screening of AIP and MEN1 variants in young patients and relatives is of clinical value.

The recurrent p.(Pro540Ser) MEN1 genetic variant should be considered nonpathogenic: A case report

Pheochromocytoma/paraganglioma (Pheo/PGL) associated with pituitary adenoma (PA) is rare in clinical practice, and a common pathogenic mechanism has been suggested owing to the germline pathogenic variants found in some cases. Our aim is to propose a reassignment for a recurrent MEN1 genetic variant found in a 54-year-old male patient with bilateral pheochromocytoma and GH-secreting PA. Pheo/PGL genes study was carried out in DNA samples from Pheo as well as PA and no pathological variants or large deletions were detected. Additionally, a MEN1 gene analysis was performed, and a heterozygous germline variant in exon 10: c.1618C>T; p.(Pro540Ser) was found. No MEN1 gene deletions/duplications were detected. In evaluating a causal relationship between the c.1618C>T MEN1 variant and both tumors, we took into account that missense variants are common pathogenic variants in MEN1, and the population frequency of this variant is too high to be considered pathogenic. His son (aged 38 and carrier) is asymptomatic, and computational analysis showed discrepancies. We propose that this recurrent variant, previously considered as likely pathogenic, subsequently as variant of uncertain significance, and likely benign should now be reclassified as benign.

Morphing projections: a new visual technique for fast and interactive large-scale analysis of biomedical datasets

MOTIVATION

Biomedical research entails analyzing high dimensional records of biomedical features with hundreds or thousands of samples each. This often involves using also complementary clinical metadata, as well as a broad user domain knowledge. Common data analytics software makes use of machine learning algorithms or data visualization tools. However, they are frequently one-way analyses, providing little room for the user to reconfigure the steps in light of the observed results. In other cases, reconfigurations involve large latencies, requiring a retraining of algorithms or a large pipeline of actions. The complex and multiway nature of the problem, nonetheless, suggests that user interaction feedback is a key element to boost the cognitive process of analysis, and must be both broad and fluid.

RESULTS

In this article, we present a technique for biomedical data analytics, based on blending meaningful views in an efficient manner, allowing to provide a natural smooth way to transition among different but complementary representations of data and knowledge. Our hypothesis is that the confluence of diverse complementary information from different domains on a highly interactive interface allows the user to discover relevant relationships or generate new hypotheses to be investigated by other means. We illustrate the potential of this approach with three case studies involving gene expression data and clinical metadata, as representative examples of high dimensional, multidomain, biomedical data.

AVAILABILITY AND IMPLEMENTATION

Code and demo app to reproduce the results available at https://gitlab.com/idiazblanco/morphing-projections-demo-and-dataset-preparation.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Pediatric Cushing's syndrome: greater risk of being overweight or obese after long-term remission and its predictive factors

OBJECTIVE

Due to the rarity of Cushing's syndrome (CS) in children and adolescents, data are scarce about BMI during active disease and following remission. Therefore, our aim was to analyze BMI after long-term remission and determine predictive factors for promptly identifying patients at risk of being overweight or obese after remission for CS.

DESIGN

Retrospective cohort study.

PATIENTS

73 patients: 58 (79.4%) had Cushing disease, 40 males (58%), median age of 12 years (IQR: 9-15). The mean follow-up time was 22.4 ± 18.2 months (range: 4-98).

METHODS

Main outcome measures: BMI, lipid profile, blood pressure, HOMA-IR.

RESULTS

At diagnosis, only eight (11%) patients had a normal weight. Although the BMI z-score at the last follow-up improved (2.0 ± 0.7 to 1.0 ± 1.2, P < 0.001), 44% remained overweight or obese after 2 years of remission according to the Kaplan-Meier curves. The BMI z-scores at the last follow-up correlated only with HOMA-IR levels (r: 0.49, P = 0.027). We found two independent factors related to reaching a normal weight: BMI z-score at diagnosis (HR: 0.156, 95% CI: 0.038-0.644; P = 0.01) and BMI z-score change at 6 ± 2 months (HR: 2.980, 95% CI:1.473-6.028; P = 0.002), which had high accuracy when a cut-off of 0.5 was used for ROC analysis (AUC = 0.828 (0.67-0.97); P < 0.001).

CONCLUSIONS

Children and adolescents with CS have a high risk of being overweight or obese after successful treatment for their disease. At risk patients can be identified quickly based on their baseline BMI and initial weight loss after surgery. Efforts should focus on adopting healthy diet and lifestyle in the immediate postoperative period.

Diagnosis, treatment and follow-up of patients with acromegaly in a clinical practice setting in Spain: the ACROPRAXIS program Delphi survey

AIM

The ACROPRAXIS program aims to describe the management of acromegaly in Spain and provide guidance.

METHODS

Ninety-three endocrinologists were organized into 13 panels to discuss the practical issues in managing acromegaly. Based on the key learnings, an online Delphi survey with 62 statements was performed, so those statements achieving consensus could be used as guidance. Statements were rated on a 9-point scale (9, full agreement; consensus > 66.6% of response in the same tertile).

RESULTS

Ninety-two endocrinologists (98.8%) answered two rounds of the survey (mean age 47.6 years; 59.8% women; median 18.5 years of experience). Consensus was achieved for 49 (79%) statements.

DIAGNOSIS

The levels of insulin-like growth factor I (IGFI) is the preferred screening test. If IGFI levels 1-1.3 ULN, the test is repeated and growth hormone (GH) after oral glucose tolerance test (OGTT) is assessed. A pituitary magnetic resonance is performed after biochemical diagnosis.

TREATMENT

Surgery is the first treatment choice for patients with microadenoma or macroadenoma with/without optical pathway compression. Pre-surgical somatostatin analogues (SSA) are indicated when surgery is delayed and/or to reduce anaesthesia-associated risks. After unsuccessful surgery, reintervention is performed if the residual tumor is resectable, while if non-resectable, SSA are administered. Follow-up First biochemical and clinical controls are performed 1-3 months after surgery. Disease remission is considered if random GH levels are < 1 µg/L or OGTT is < 1 or ≤ 0.4 µg/L, depending on the assay's sensitivity.

CONCLUSION

Current clinical management for acromegaly is homogeneous across Spain and generally follows clinical guidelines.

Epigenetic Deregulation of Protocadherin PCDHGC3 in Pheochromocytomas/Paragangliomas Associated With SDHB Mutations

CONTEXT

SDHB mutations are found in an increasing number of neoplasms, most notably in paragangliomas and pheochromocytomas (PPGLs). SDHB-PPGLs are slow-growing tumors, but ∼50% of them may develop metastasis. The molecular basis of metastasis in these tumors is a long-standing and unresolved problem. Thus, a better understanding of the biology of metastasis is needed.

OBJECTIVE

This study aimed to identify gene methylation changes relevant for metastatic SDHB-PPGLs.

DESIGN

We performed genome-wide profiling of DNA methylation in diverse clinical and genetic PPGL subtypes, and validated protocadherin γ-C3 (PCDHGC3) gene promoter methylation in metastatic SDHB-PPGLs.

RESULTS

We define an epigenetic landscape specific for metastatic SDHB-PPGLs. DNA methylation levels were found significantly higher in metastatic SDHB-PPGLs than in SDHB-PPGLs without metastases. One such change included long-range de novo methylation of the PCDHA, PCDHB, and PCDHG gene clusters. High levels of PCDHGC3 promoter methylation were validated in primary metastatic SDHB-PPGLs, it was found amplified in the corresponding metastases, and it was significantly correlated with PCDHGC3 reduced expression. Interestingly, this epigenetic alteration could be detected in primary tumors that developed metastasis several years later. We also show that PCDHGC3 down regulation engages metastasis-initiating capabilities by promoting cell proliferation, migration, and invasion.

CONCLUSIONS

Our data provide a map of the DNA methylome episignature specific to an SDHB-mutated cancer and establish PCDHGC3 as a putative suppressor gene and a potential biomarker to identify patients with SDHB-mutated cancer at high risk of metastasis who might benefit from future targeted therapies.

MEN1-associated primary hyperparathyroidism in the Spanish Registry: clinical characterictics and surgical outcomes

Primary hyperparathyroidism is the most frequent manifestation of multiple endocrine neoplasia type 1 (MEN1) syndrome. Bone and renal complications are common. Surgery is the treatment of choice, but the best timing for surgery is controversial and predictors of persistence and recurrence are not well known. Our study describes the clinical characteristics and the surgical outcomes, after surgery and in the long term, of the patients with MEN1 and primary hyperparathyroidism included in the Spanish Registry of Multiple Endocrine Neoplasia, Pheochromocytomas and Paragangliomas (REGMEN). Eighty-nine patients (49 men and 40 women, 34.2 ± 13 years old) were included. Sixty-four out of the 89 underwent surgery: a total parathyroidectomy was done in 13 patients, a subtotal parathyroidectomy in 34 and a less than subtotal parathyroidectomy in 15. Remission rates were higher after a total or a subtotal parathyroidectomy than after a less than subtotal (3/4 and 20/22 vs 7/12, P < 0.05), without significant differences in permanent hypoparathyroidism (1/5, 9/23 and 0/11, N.S.). After a median follow-up of 111 months, 20 of the 41 operated patients with long-term follow-up had persistent or recurrent hyperparathyroidism. We did not find differences in disease-free survival rates between different techniques, patients with or without permanent hypoparathyroidism and patients with different mutated exons, but a second surgery was more frequent after a less than subtotal parathyroidectomy.

Optical Imaging Technology: A Useful Tool to Identify Remission in Cushing Disease After Surgery

We recently reported the use of optical imaging technology to quantify facial plethora in endogenous Cushing syndrome (CS). In the present study, we studied a larger cohort of patients with Cushing disease (CD) and examined water content fraction as well as blood volume fraction as bio-optic markers for determining the efficacy of this methodology as a predictor of lasting remission after surgery for CS. We imaged 49 patients before and after transsphenoidal surgery (TSS) for Cushing disease (CD); 22 patients were also seen at 3-6 months, and 13 patients 12 months post-operatively. On all patients, we used multi-spectral imaging (MSI) to evaluate hemodynamic distributions as well as water content at a specific area of the face. We found a decrease in blood volume fraction after vs. before surgical treatment in the tested facial area in 37 of the 40 patients, as determined with biochemical markers (p<0.001). All patients that were followed up for up to 12 months showed the same decrease from preoperative values and they remained in remission from CD. We conclude that MSI can be used for the evaluation of remission from CD, at least in the immediate post-operative period and up to one year after surgery. The use of this technology can supplement biochemical and other testing for the evaluation of the various treatment modalities available for patients with CD.

Clinical significance and peculiarities of succinate dehydrogenase B and hypoxia inducible factor 1α expression in parasympathetic versus sympathetic paragangliomas

BACKGROUND

Succinate dehydrogenase subunit B (SDHB) immunohistochemistry was considered a valuable tool to identify patients with inherited paraganglioma/pheochromocytoma (PGL/PCC). However, previous studies jointly analyzed 2 related but clinically distinct entities, parasympathetic head and neck paragangliomas (HNPGLs) and sympathetic PCCs/PGLs. Additionally, a role for hypoxia inducible factor-1α (HIF-1α) as a biomarker for succinate dehydrogenase (SDHx)-mutated tumors has not been studied. Here, we evaluated the utility of SDHB/HIF-1α proteins in HNPGLs and PCCs/PGLs as clinically useful biomarkers.

METHODS

The SDHB/succinate dehydrogenase subunit A (SDHA)/HIF-1α immunohistochemistry analysis was performed in 158 genetically defined patients.

RESULTS

Similarly to PCCs/PGLs, SDHB immune-negativity correlated with SDHx-mutations in HNPGLs (P < .0001). The HIF-1α stabilization was associated with SDHx-mutations in HNPGLs (P = .020), not in PCCs/PGLs (P = .319). However, 25% of SDHx-HNPGLs lacked HIF-1α positive cells.

CONCLUSION

As in PCCs/PGLs, SDHB immunohistochemistry in HNPGLs is a valuable method for identification of candidates for SDHx-genetic testing. On the contrary, although SDHx mutations may favor HIF-1α stabilization in HNPGLs, this is not a clinically useful biomarker.

Genetics of micronodular adrenal hyperplasia and Carney complex

Micronodular bilateral adrenal hyperplasia (MiBAH) is a rare cause of adrenal Cushing syndrome (CS). The investigations carried out on this disorder during the last two decades suggested that it could be divided into at least two entities: primary pigmented nodular adrenocortical disease (PPNAD) and isolated micronodular adrenocortical disease (i-MAD). The most common presentation of MiBAH is familial PPNAD as part of Carney complex (CNC) (cPPNAD). CNC, associated with multiple endocrine and non-endocrine neoplasias, was first described in 1985 in 40 patients, 10 of whom were familial cases. In 2000, we identified inactivating germline mutations of the PRKAR1A gene, encoding the regulatory subunit type 1α (RIα) of protein kinase A (PKA), in the majority of patients with CNC and PPNAD. PRKAR1A mutations causing CNC lead to increased PKA activity. Since then, additional genetic alterations in the cAMP/PKA signaling pathway leading to increased PKA activity have been described in association with MiBAH. This review summarizes older and recent findings on the genetics and pathophysiology of MiBAH, PPNAD, and related disorders.

Role of VHL, HIF1A and SDH on the expression of miR-210: Implications for tumoral pseudo-hypoxic fate

The hypoxia-inducible factor 1α (HIF-1α) and its microRNA target, miR-210, are candidate tumor-drivers of metabolic reprogramming in cancer. Neuroendocrine neoplasms such as paragangliomas (PGLs) are particularly appealing for understanding the cancer metabolic adjustments because of their associations with deregulations of metabolic enzymes, such as succinate dehydrogenase (SDH), and the von Hippel Lindau (VHL) gene involved in HIF-1α stabilization. However, the role of miR-210 in the pathogenesis of SDH-related tumors remains an unmet challenge. Herein is described an in vivo genetic analysis of the role of VHL, HIF1A and SDH on miR-210 by using knockout murine models, siRNA gene silencing, and analyses of human tumors. HIF-1α knockout abolished hypoxia-induced miR-210 expression in vivo but did not alter its constitutive expression in paraganglia. Normoxic miR-210 levels substantially increased by complete, but not partial, VHL silencing in paraganglia of knockout VHL-mice and by over-expression of p76del-mutated pVHL. Similarly, VHL-mutated PGLs, not those with decreased VHL-gene/mRNA dosage, over-expressed miR-210 and accumulate HIF-1α in most tumor cells. Ablation of SDH activity in SDHD-null cell lines or reduction of the SDHD or SDHB protein levels elicited by siRNA-induced gene silencing did not induce miR-210 whereas the presence of SDH mutations in PGLs and tumor-derived cell lines was associated with mild increase of miR-210 and the presence of a heterogeneous, HIF-1α-positive and HIF-1α-negative, tumor cell population. Thus, activation of HIF-1α is likely an early event in VHL-defective PGLs directly linked to VHL mutations, but it is a late event favored but not directly triggered by SDHx mutations. This combined analysis provides insights into the mechanisms of HIF-1α/miR-210 regulation in normal and tumor tissues potentially useful for understanding the pathogenesis of cancer and other diseases sharing similar underpinnings.

SDHC Promoter Methylation, a Novel Pathogenic Mechanism in Parasympathetic Paragangliomas

CONTEXT

Germline mutations in the succinate dehydrogenase A, B, C, and D genes (collectively, SDHx) predispose to the development of paragangliomas (PGLs) arising at the parasympathetic or sympathetic neuroendocrine systems. SDHx mutations cause absence of tumoral immunostaining for SDHB. However, negative SDHB immunostaining has also been found in a subset of PGLs that lack SDHx mutations.

SETTINGS

Here, we report the comprehensive molecular characterization of one such a tumor of parasympathetic origin compared with healthy paraganglia and other PGLs with or without SDHx mutations.

RESULTS

Integration of multiplatform data revealed somatic SDHC methylation and loss of the 1q23.3 region containing the SDHC gene. This correlated with decreased SDHC messenger RNA (mRNA) and protein levels. Furthermore, another genetic event found affected the VHL gene, which showed a decreased DNA copy number, associated with low VHL mRNA levels, and an absence of VHL protein detected by immunohistochemistry. In addition, the tumor displayed a pseudohypoxic phenotype consisting in overexpression of the hypoxia-inducible factor (HIF)-1α and miR-210, as well as downregulation of the iron-sulfur cluster assembly enzyme (ISCU) involved in SDHB maturation. This profile resembles that of SDHx- or VHL-mutated PGLs but not of PGLs with decreased VHL copy number, pointing to SDHC rather than VHL as the pathogenic driver.

CONCLUSIONS

Collectively, these findings demonstrate the potential importance of both the SDHC epigenomic event and the activation of the HIF-1α/miR-210/ISCU axis in the pathogenesis of SDHx wild-type/SDHB-negative PGLs. To our knowledge, this is the first case of a sporadic parasympathetic PGL that carries silencing of SDHC, fulfilling the two-hit Knudson's model for tumorigenesis.

Loss-of-function mutations in the CABLES1 gene are a novel cause of Cushing's disease

The CABLES1 cell cycle regulator participates in the adrenal-pituitary negative feedback, and its expression is reduced in corticotropinomas, pituitary tumors with a largely unexplained genetic basis. We investigated the presence of CABLES1 mutations/copy number variations (CNVs) and their associated clinical, histopathological and molecular features in patients with Cushing's disease (CD). Samples from 146 pediatric (118 germline DNA only/28 germline and tumor DNA) and 35 adult (tumor DNA) CD patients were screened for CABLES1 mutations. CNVs were assessed in 116 pediatric CD patients (87 germline DNA only/29 germline and tumor DNA). Four potentially pathogenic missense variants in CABLES1 were identified, two in young adults (c.532G > A, p.E178K and c.718C > T, p.L240F) and two in children (c.935G > A, p.G312D and c.1388A > G, and p.D463G) with CD; no CNVs were found. The four variants affected residues within or close to the predicted cyclin-dependent kinase-3 (CDK3)-binding region of the CABLES1 protein and impaired its ability to block cell growth in a mouse corticotropinoma cell line (AtT20/D16v-F2). The four patients had macroadenomas. We provide evidence for a role of CABLES1 as a novel pituitary tumor-predisposing gene. Its function might link two of the main molecular mechanisms altered in corticotropinomas: the cyclin-dependent kinase/cyclin group of cell cycle regulators and the epidermal growth factor receptor signaling pathway. Further studies are needed to assess the prevalence of CABLES1 mutations among patients with other types of pituitary adenomas and to elucidate the pituitary-specific functions of this gene.

Corticotropinoma as a Component of Carney Complex

Known germline gene abnormalities cause one-fifth of the pituitary adenomas in children and adolescents, but, in contrast with other pituitary tumor types, the genetic causes of corticotropinomas are largely unknown. In this study, we report a case of Cushing disease (CD) due to a loss-of-function mutation in PRKAR1A, providing evidence for association of this gene with a corticotropinoma. A 15-year-old male presenting with hypercortisolemia was diagnosed with CD. Remission was achieved after surgical resection of a corticotropin (ACTH)-producing pituitary microadenoma, but recurrence 3 years later prompted reoperation and radiotherapy. Five years after the original diagnosis, the patient developed ACTH-independent Cushing syndrome, and a diagnosis of primary pigmented nodular adrenocortical disease was confirmed. A PRKAR1A mutation (c.671delG, p.G225Afs*16) was detected in a germline DNA sample from the patient, which displayed loss of heterozygosity in the corticotropinoma. No other germline or somatic mutations of interest were found. As corticotropinomas are not a known component of Carney complex (CNC), we performed loss of heterozygosity and messenger RNA stability studies in the patient's tissues, and analyzed the effect of Prkar1a silencing on AtT-20/D16v-F2 mouse corticotropinoma cells. No PRKAR1A defects were found among 97 other pediatric CD patients studied. Our clinical case and experimental data support a role for PRKAR1A in the pathogenesis of a corticotroph cell tumor. This is a molecularly confirmed report of a corticotropinoma presenting in association with CNC. We conclude that germline PRKAR1A mutations are a novel, albeit apparently infrequent, cause of CD.

RET Cys634Arg mutation confers a more aggressive multiple endocrine neoplasia type 2A phenotype than Cys634Tyr mutation

OBJECTIVE

Specific germline mutations in the RET proto-oncogene are correlated with clinical features in multiple endocrine neoplasia type 2A (MEN2A); however, data are scarce regarding differences in clinical profiles dependent on the type of nucleotide and amino acid substitution at the same codon. We aimed to analyse differences in clinical risk profiles and outcomes among different amino acids encoded by codon 634.

DESIGN

The study was retrospective and multicentric.

METHODS

We collected data included in the Spanish Online National Database from patients with MEN2A carrying a RET proto-oncogene mutation on codon 634. The mean follow-up time was 7.6±6.9 years (1-32).

RESULTS

Patients (n=173) from 49 unrelated families were C634Y carriers, and 26 patients from eight different families had C634R mutation. We found higher penetrance of medullary thyroid carcinoma, phaeochromocytoma and hyperparathyroidism (P<0.001, P=0.007 and P<0.001 respectively) in C634R carriers than in C634Y carriers. The Kaplan-Meier estimate of cumulative lymph node and distant metastases rates showed that these events occurred earlier in patients harbouring the C634R mutation (P<0.001). A multivariate adjusted Cox regression analysis indicated that the C634R mutation was an independent factor for persistent/recurrent disease (hazard ratio, 3.17; 95% CI: 1.66-6.03; P<0.001).

CONCLUSIONS

Our results suggest that there could be clinical differences caused by different amino acid substitutions at codon 634; specifically, the C634R mutation was associated with a more aggressive MEN2A phenotype than the C634Y mutation.

Multiple endocrine neoplasia type 1 (MEN1): clinical heterogeneity in a large family with a nonsense mutation in the MEN1 gene (Trp471Stop)

OBJECTIVE

Familial multiple endocrine neoplasia type 1 (MEN1) is an hereditary dominant trait characterized by tumours of the parathyroids, anterior pituitary and endocrine pancreatic glands, among others. The MEN1 gene has recently been cloned, and MEN1-mutations have been identified in several families as well as in a number of sporadic cases. The aim of this study was to search for mutations in a large MEN1-family in order to define the clinical heterogeneity among mutation-carriers. We also analysed DNA from several tumour tissues in order to test the 'two hit' model for inactivation of the MEN1 gene.

PATIENTS AND METHODS

We searched for mutations in the MEN1-gene in members of a large MEN1-family. A total of 11 affected and 4 healthy at risk individuals were analysed. DNA was obtained and exons 1 to 10 of the MEN1-gene were PCR-amplified and subjected to automated-direct sequencing. In addition, we isolated DNA from parathyroid tumours of two family members, and compared this DNA with that of the normal tissue counterpart to define if the normal copy of the MEN1-gene was deleted.

RESULTS

G to A change at nucleotide 7640 (exon 10) that would convert Trp to Stop at codon 471 was found. This mutation was identified in eleven affected individuals, as well as in four healthy (asymptomatic) family members. These patients showed a wide spectrum of clinical symptoms and ages of presentation. Comparison of normal and tumour DNAs showed the loss of the normal (non-mutated) copy of MEN1 gene in the tumour tissue.

CONCLUSION

The different ages of disease presentation and the heterogeneity of symptoms among carriers of the Trp471Stop mutation, which would lead to the synthesis of a truncated non-functional protein, suggest that clinical heterogeneity is a characteristic of MEN1 independent of the type of mutation. Finally, the lack of amplification of the normal MEN1-allele on DNA from parathyroid tumours of two family members indicates that MEN1 is a tumour suppressor gene, the second hit that inactivates the normal copy in mutation carriers being a deletion.

Rhombomere-specific origin of branchial and visceral motoneurons of the facial nerve in the rat embryo

The goal of this study was to localize selectively the facial nerve branchial and visceral motoneurons in the rat embryo hindbrain. This was achieved by injecting dextran amines into the peripheral facial nerve on embryos maintained in an artificial cerebrospinal fluid. Sprague-Dawley rat embryos 13, 14, and 15 days old (E13, E14, E15) were obtained by cesarean section. Branchial motoneurons were first labeled at E13. They were close to the midline and migrated from rhombomere (r) 4 toward r5 and r6. By E15, they had migrated caudally and ventrolaterally into the former location of r6. Most of them had reached their "adult" position by E15. Another group of motoneurons, the accessory facial nucleus, was found in r4 at E13 and in corresponding regions at later stages. Visceral motoneurons were labeled from the periphery at all stages. At E13, they were mainly in r5 but also in r2, r3, r4, and r6. At E14, most of them had migrated laterally, and, by E15, they were in the prospective parvocellular reticular formation. They could be divided into two subgroups: a more rostral one with fibers that made loops close to the midline and a more caudal one with fibers that went directly to the exit. The findings presented here show that most branchial and visceral motoneurons of the facial nerve are born in different and specific rhombomeres. Interestingly, developmental genes are expressed specifically in these rhombomeres and could be involved in the genesis of the facial and superior salivatory nuclei.