Adrenal lesions often occur in patients with multiple endocrine neoplasia type 1 (MEN1), mostly adrenal cortical adenomas (ACAs), although the frequency of adrenal cortical carcinomas (ACCs) is higher than in the general population. The coexistence of benign and malignant masses has seldom been documented, leaving open the question of ACC progression from benign forms. We report a comprehensive genetic characterization of three adrenal cortical tumor samples obtained from a familial MEN1 patient, operated for the rapid progression of an initially stable nonfunctional adrenal incidentaloma. Histologically, the tumor consisted of a small ACA contiguous to a large ACC, which subsequently relapsed. Exome sequencing of ACC, ACA and recurrence evidenced a MEN1 loss of heterozygosity (LOH) in ACC but not in ACA, where, however, a second hit driven by alternative mechanisms could not be excluded. The majority of the ACA variants were found to co-occurred in ACC (n = 36/42) and were benign, except for two of unknown significance in KANK1 and REN genes, described as associated with renal cancer. Among variants shared between ACC and its recurrence (n = 69), 11 were Tier III, while 2 affecting TP53 and NF1 genes were pathogenic. Bioinformatic clonal evolution analysis identified one clone − characterized by TP53 and NF1 mutations − absent in ACA but present in ACC and recurrence, as well as 2 clones shared between ACA and ACC but lost in the recurrence. In conclusion, comparative Whole Exome Sequencing (WES) analysis of three adrenal tumors in a MEN1 patient suggests a possible relationship between malignant and benign lesions occurring in MEN1 patients, without, however, demonstrating any causal adenoma-to-carcinoma progression driven by MEN1 LOH. Overall, these data further suggest an increased risk of MEN1 patients to develop adrenocortical malignancy.

OBJECTIVE:Mitotane is e first-line medical treatment for adrenocortical carcinoma (ACC). Mitotane has substantial dr awbacks, including severe toxicity and contralateral gland destruction, whilst effective in only 25-30% of ACCs. To improve patient selection for mitotane therapy, this study aimed to identify tissue biomarkers associated with in vitro mitotane response. DESIGN:Retrospective cohort study. METHODS:We performed transcriptomic and proteomic analyses on fresh-frozen human ACC tissues classified as responders (n=13), partial responders (n=10), or non-responders (n=7) based on in vitro mitotane-induced inhibition of cell proliferation. RESULTS:Responders showed distinct transcriptomic and proteomic signatures compared with partial and non-responders, whereas fewer differences were found between the latter groups. Integrating transcriptomic and clinicopathological data indicated that responders frequently had cortisol-producing ACC with metastases or nodal involvement. Furthermore, their transcriptomes aligned with aggressive, proliferative ACC subtypes described previously. Differential expression analysis identified 718 genes and 60 proteins that distinguished responders from non-responders. Pathway and network analyses revealed upregulation of cell cycle and collagen related genes and downregulation of mitochondria related genes and proteins in responders. CONCLUSIONS:In summary, transcriptomic and proteomic profiling offers promise to predict mitotane response in ACC. Our findings suggest that responders exhibit features of aggressive ACC, with distinct molecular characteristics that could serve as biomarkers for treatment selection.

OBJECTIVE:Craniopharyngiomas are classified as adamantinomatous or papillary subtypes. Papillary craniopharyngiomas harbor BRAF V600E mutations and demonstrate high response rates to BRAF/MEK inhibition. Craniopharyngiomas involving the hypothalamus are common and carry high surgical morbidity, including endocrine, metabolic, and neurocognitive complications. Therefore, reliable preoperative identification of papillary hypothalamic tumors could support consideration of biopsy followed by targeted therapy, potentially avoiding high-risk surgery. DESIGN:This study is a single-center retrospective study. METHODS:We retrospectively analyzed 61 adult patients with hypothalamic craniopharyngiomas. We defined a novel MRI biomarker, the polystyrene beads sign, as an agglomerate of small, rounded, contrast-enhancing nodules on high-resolution T1-weighted post-contrast MRI. Six independent clinicians, blinded to histopathology, evaluated the presence of the sign. Diagnostic performance (sensitivity, specificity, accuracy) and intra- and interrater reliability were assessed. RESULTS:The polystyrene beads sign identified papillary tumors with 92% sensitivity, 98% specificity, and 96% overall diagnostic accuracy. Intrarater reliability across 2 separate readings was high, and interrater reliability among all 6 clinicians was excellent. After a brief calibration session, the sign was consistently recognizable and distinguishable from enhancement patterns observed in adamantinomatous tumors. CONCLUSIONS:The polystyrene beads sign is a simple and reproducible preoperative MRI marker that may help identify papillary hypothalamic craniopharyngiomas. These findings support further evaluation in multicenter studies before clinical implementation. Its recognition may contribute to imaging-based diagnostic strategies, including selection of patients for confirmatory biopsy, molecular testing, and subsequent targeted therapy in appropriate cases.

Introduction Cushing’s disease (CD) has traditionally been approached through a binary paradigm based on MRI findings, distinguishing MRI-positive from MRI-negative cases. However, this dichotomy incompletely reflects the heterogeneity of corticotroph tumors and complexity of intraoperative decision-making. Research question We propose a stepwise surgical strategy that moves beyond this binary stratification by conceptualizing CD as a spectrum integrating imaging, biochemical, and intraoperative findings. Methods This retrospective purposefully selected illustrative case series was drawn from a prospective database of 983 patients treated for CD between 2006 and 2025. All underwent mononostril endoscopic transsphenoidal surgery by an expert pituitary surgical team. Seven cases were chosen to illustrate the CD spectrum presentations, including MRI-positive lesions with invasive features, MRI-equivocal findings, and MRI-negative disease. A stepwise algorithm integrating preoperative imaging, functional analysis, and intraoperative findings guided surgical exploration and resection. Results Seven patients were included. In MRI-visible lesions, targeted adenomectomy was performed, with extension to basal dura or cavernous sinus wall when indicated. In MRI-negative or equivocal cases, exploration was guided by repeat imaging, heterogeneous MRI signal, venous sampling, and/or FET-PET. When tumor tissue was identified, selective or enlarged adenomectomy was performed according to infiltration patterns. Early endocrine remission was achieved in 6 patients, while one patient achieved postoperative eucortisolism. Transient diabetes insipidus was the only postoperative complication. Conclusion CD may be reconsidered beyond a binary MRI-based paradigm, as a spectrum of scenarios. A stepwise surgical strategy better reflects disease heterogeneity and provides a practical framework for surgical decision-making, particularly in MRI-negative or MRI-equivocal cases.

BACKGROUND:Aggressive evolution of PitNETs is rare; metastatic spread is even more. Defining aggressiveness and malignancy is challenging, subsequently hard to predict, and to understand. The aim was to provide a molecular definition of aggressiveness using genomic approaches. METHODS:PitNETs from 206 patients were included. Associations between 9 clinicopathological features of aggressiveness and PitNETs' omics were explored. Omics included transcriptome, DNA methylation, chromosomal alterations, and mutations. Clonal tumor evolution was monitored in 7 patients. RESULTS:Among the 9 clinicopathological features of aggressiveness, only rapid progression, progression after radiotherapy, Ki67/MIB1 proliferation index ≥10%, temozolomide treatment, metastases, and specific death were associated with specific omics signatures, while tumour maximal diameter ≥40 mm, cavernous, and sphenoid invasion were not. The omic signatures associated with these features of aggressiveness overlapped but remained distinct between corticotroph and mammo-somato-thyrotroph lineages. For each lineage, a common signature of aggressiveness was identified, associating a proliferative transcriptome signature and DNA hypermethylation. Alterations in specific genes were associated with aggressive features, including a novel PitNET gene, LRP1B, and known cancer genes (TP53, CDKN2A), while USP8 and GNAS alterations were not. Integration of gene alterations with methylome and transcriptome signatures isolated a subset of molecularly aggressive PitNETs. Molecular signatures were stable during the course of the disease, despite evolution toward aggressiveness and potential clonal divergence. CONCLUSION:This systematic analysis of clinicopathological features of aggressiveness using an integrated multiomic approach establishes a histomolecular definition of aggressiveness in PitNETs. Prospective cohort studies are needed to validate these molecular signatures and establish their prognostic value.

Bilateral macronodular adrenocortical disease (BMAD) is currently described as composed of 4 microscopic subtypes (subtype 1 to 4) and 3 molecular groups (ARMC5-altered, KDM1A-altered, and unknown). Little is known about protein heterogeneity and its links with BMAD characteristics. The aim of this work is to study the protein signatures of BMADs and their correlations with microscopy and genetics. Liquid chromatography and tandem mass spectrometry (LC-MS/MS) was performed on 24 BMADs: 7 ARMC5, 4 KDM1A, 13 non-KDM1A, non-ARMC5 BMADs and 2 normal adrenal glands and 10 adrenal adenomas as control. Unsupervised clustering divided BMAD samples into 3 proteomic groups. The first group is composed of ARMC5-altered BMADs (subtype 1) and is characterized by an accumulation of RNA polymerase II (Pol II) subunits. The second, composed of KDM1A-altered (subtype 2) patients and subtype 4 BMADs (oncocytic), is characterized by an accumulation of cholesterol biosynthesis enzymes (such as FDFT1). The last group has no specific signature detected and is composed of subtypes 1 and 3 BMAD without ARMC5 alteration. Immunohistochemical analyses with anti Pol II subunits and cholesterol biosynthesis enzymes correlate with the three proteomic groups. Proteins specifically accumulated in ARMC5-altered BMADS such as POLR2A could be used as biomarkers to detect ARMC5 alterations. Data are available via ProteomeXchange with identifier PXD070500. Our study explores BMAD proteome using LC-MS/MS. The 3 proteomic groups mostly overlap the 4 microscopic and 3 molecular groups of BMAD. Accumulation of Pol II subunits consistent with the described role of ARMC5 could play a role in the pathogenesis of these BMADs. KDM1A-altered (subtype 2) and subtype 4 BMADs showed an accumulation of proteins involved in lipid metabolism that could contribute to hypercortisolism. These results reveal specific protein patterns pointing to various cellular processes opening new perspectives to understand BMAD pathophysiology and provide new tools for the pathologists.

OBJECTIVE:To develop a deep learning model to differentiate benign from malignant adrenal lesions. MATERIALS AND METHODS:A total of 380 patients with 385 pathologically confirmed adrenal lesions (101 malignant, 284 benign) were retrospectively included. Adrenal lesions were manually segmented on CT images and analyzed in a deep learning pipeline aimed at differentiating benign from malignant lesions. Four predictive models were developed that incorporated combinations of radiological data (tumor size, and spontaneous attenuation) and non-radiological data (i.e., medical history and laboratory results). Data of 267 patients were used as a training set and those of 113 patients for the test set. The diagnostic capabilities of the four models were estimated using sensitivity, specificity, accuracy, and areas under the receiver operating characteristic curves (AUC) using histopathological findings as the gold standard. The reproducibility of manual segmentation was estimated using the Dice similarity coefficient after blinded resegmentation of 40 adrenal lesions by an independent radiologist. RESULTS:Segmentation reproducibility achieved a mean Dice similarity coefficient of 0.92 ± 0.03 (range: 0.72-0.97). The most accurate model, which combined clinical, biological, and radiological data, achieved 84.2% accuracy (95% confidence interval: 79.9, 88.6) and an AUC of 0.93 (95% confidence interval: 89.9, 97.9) in the test set for diagnosis of malignant adrenal lesion. CONCLUSION:A deep learning model integrating preoperative clinical, biological, and radiological features demonstrates high capabilities in differentiating benign from malignant adrenal lesions on initial CT examination.

Background: Adrenocortical carcinoma (ACC) is a rare malignancy with limited therapeutic options and poor prognosis in advanced stages. Clinico-pathological markers, such as Ki67 and ENSAT stage remain insufficient to fully predict recurrence or treatment response, highlighting the need for molecular characterization.Molecular classification: Omic approaches, including transcriptomics, DNA methylation and chromosomal alteration profiling have consistently identified two distinct ACC subtypes “C1A” and “C1B”. C1A tumors, overexpressing proliferation genes, are associated to poorer outcomes. C1B tumors however, are characterized by their immune signature and are of better prognosis. Single-cell analyses have helped understanding the mechanisms underlying these differences, hinting at a central role of intratumoral steroid differentiation in shaping the immune microenvironment.Clinical and therapeutic perspectives: Transcriptome sequencing from paraffin-embedded samples are bringing molecular classification closer to routine care, with ongoing prospective trials evaluating its feasability. Genomic classification represents a major step in ACC management and understanding, offering improved prognostic stratification and orienting future therapeutic strategies.

Adrenocortical carcinoma (ACC) is a rare and aggressive malignancy arising from the adrenal cortex. This tumor shows suggestive imaging features on computed tomography (CT), which include a large size, internal heterogeneity and various degrees of internal necrosis. Accurate characterization of ACC with imaging is essential to ensure prompt and appropriate management and avoid useless biopsy or delayed surgery. Magnetic resonance imaging (MRI) provides additional information with respect to the internal content of ACC by comparison with CT. Recent studies evaluating the capabilities of radiomics have shown encouraging results in the characterization of ACC and differentiation from other adrenal masses. Surgical resection remains the primary treatment for localized ACC. Complete surgical resection (i.e., R0 resection) offers the best chance for long-term survival for patients with ACC. Preoperative planning with imaging should be performed to identify local extent of ACC into the liver, the ipsilateral kidney, and the inferior vena cava as well as to exclude distant metastases. A precise preoperative assessment is critical to anticipate the radicality of surgery and best manage potential surgical complications. This review article aims to provide a thorough overview of the current role of CT and MRI in the diagnosis and preoperative planning of ACC.

The emergence of genomics has opened new fields in molecular biology and genetics of adrenocortical cancer (ACC). The most common germline alteration is TP53 mutation, in part of Li–Fraumeni syndrome. Recently, genomic studies have identified ACC as a Lynch syndrome associated tumor. Somatic genetics has also benefit from the genomic revolution. Pan-genomic studies converge in a new classification of ACC, with three groups characterized by distinct molecular alterations—gene and miR expression, mutations, chromosome profiles and methylation—and associated with very different outcomes. Targeted markers derived from genomics have been developed for routine prognostication of these tumors.

OBJECTIVE:Dopamine agonists and somatostatin analogs are commonly used in prolactinomas and somatotropinomas. Response to these therapies is heterogeneous. Whether resistance is linked to specific tumor subtypes or to shared mechanisms of resistance is not known. The aim was to explore distinct molecular subtypes of prolactinomas and somatotropinomas and their association with response to treatment. METHODS:The transcriptome of 46 prolactinomas and 58 somatotropinomas was analyzed. Unsupervised classifications were generated and tested for association with histological and clinical data, including response to treatment. RESULTS:Four subtypes of prolactinomas were identified, with variable sensitivity to dopamine agonists (P < 10-4). Sensitive tumors accumulated in the subgroup with the highest DRD2 expression, while resistant tumors accumulated in the 3 remaining ones, enriched in genes related to cAMP metabolism, to mitochondrial and ribosomal activity, and to immunity, respectively. Sparsely granulated somatotropinomas (N = 16) presented a separated molecular entity, mixing tumors resistant and sensitive to somatostatin analogs. The remaining somatotropinomas were classified into 5 subtypes, with variable sensitivity to somatostatin analogs (P < 10-4). Sensitive tumors accumulated in 3 subgroups, characterized by GNAS somatic mutation, PIT1 and SF1 coexpression, and the stem-cell marker SOX2 expression, respectively. Resistant tumors accumulated in the 2 remaining ones, enriched in genes related to cell cycle and to mesenchymal differentiation, respectively. Somatostatin receptor 2 (SSTR2) expression was associated with response to somatostatin analogs in sparsely granulated somatotropinomas (P = .022), but not in other somatotropinomas (P = .923). CONCLUSIONS:Prolactinomas and somatotropinomas were classified into distinct transcriptomic groups. Resistance to medical therapies was linked to distinct tumor subtypes, suggesting distinct mechanisms of resistance.

OBJECTIVE:Individual patients' data sharing requires interoperability, security, ethical, and legal compliance. The aim was to assess the landscape and sharing capacities between endocrine researchers. DESIGN:A standardized survey (SurveyMonkey®) with 67 questions was sent to European Network for the Study of Adrenal Tumors centers. METHODS:Answers were counted as absolute numbers and percentages. Comparisons between inclusiveness target countries (ITC) and non-ITC (defined by Cooperation in Science & Technology Action) were performed using Fisher's exact test. RESULTS:Seventy-three centers from 34 countries answered the survey. Electronic health record (EHR) systems are now the main source of data (90%). However, significant variability was reported, entailing >35 EHR providers, and variable data collected. Variable stakeholders' implication for enabling data sharing was reported, with more lawyers (P = .023), patient representatives (P < .001), ethicists (P = .002), methodologists (P = .023), and information technology experts (P < .001) in non-ITC centers. Implication of information technologies experts for data collection and sharing was underwhelming (33%). Funding for clinical research was higher in non-ITC than in ITC for clinical trials (P = .01) and for registry-based and cohort studies (P = .05). However, for retrospective studies addressing a specific clinical question, the funding was either very low (<10%) or nonexistent for both ITC and non-ITC (37% and 46%, respectively), with no dedicated funding for information technology (86%) and ethical and regulatory aspects (88%). CONCLUSIONS:In the absence of dedicated funding for retrospective research, current requirements for data sharing are obstacles.

BACKGROUND:Adrenal incidentalomas are found in 3-10% of adults undergoing abdominal imaging. Of these, 30-50% are responsible for mild autonomous cortisol secretion (MACS), which is frequently associated with hypertension. The impact of adrenalectomy on hypertension in patients with unilateral incidentalomas and MACS remains uncertain. The aim of the CHIRACIC study was to prospectively assess the impact of surgical excision of the incidentaloma on blood pressure with a randomised trial combining accurate blood pressure measurement and standardisation of antihypertensive treatment. METHODS:CHIRACIC was a multicentre, superiority, open-label, parallel, randomised controlled trial performed at 17 university hospitals in France, Italy, and Germany. Adults with hypertension with MACS entered a run-in phase to confirm hypertension with multiple home blood pressure measurements (HBPM) before blood pressure was normalised with standardised stepped-care antihypertensive treatment. Eligible participants were then randomly assigned (1:1) to adrenalectomy or conservative management. Randomisation was blocked (random block size of 4 and 6) and stratified by intensity of antihypertensive treatment. Participants were followed up for 13 months and systematic attempts were made to gradually reduce antihypertensive treatment. The primary endpoint was the proportion of normotensive participants using HBPM who reduced their antihypertensive treatment in the intention-to-treat population at study completion. Key secondary endpoints included 24 h ambulatory blood pressure measurement (ABPM), mean change in antihypertensive treatment, and the proportion of participants with antihypertensive treatment at study completion. This study was registered with ClinicalTrials.gov, NCT02364089, and is completed. FINDINGS:Between April 9, 2015 and Nov 23, 2022, 78 patients were enrolled, and 52 eligible participants were randomly assigned to adrenalectomy (n=26, 23 underwent adrenalectomy and completed the study) or conservative management (n=26, 25 completed the study). The median age of participants was 63·3 years (IQR 57·4-68·2) and 36 (69%) were female. At study completion, a reduction in antihypertensive treatment with normal HBPM was observed in 12 (46%) of 26 participants treated with adrenalectomy and in four (15%) of 26 treated conservatively (adjusted risk difference [RD] 0·34 [95% CI 0·11 to 0·58]; p=0·0038). Similar results of smaller magnitude were observed for systolic blood pressure during 24 h ABPM. There were ten (43%) of 23 participants still needing antihypertensive treatment in the adrenalectomy group and 24 (96%) of 25 in the conservative management group (adjusted RD -0·58 [95% CI -0·78 to -0·38]; p<0·0001). Mean antihypertensive treatment step was 0·8 (SD 1·1) in the adrenalectomy group and 3·0 (1·4) in the conservative management groups (adjusted difference -2·05 [95% CI -2·61 to -1·50]; p<0·0001]. The number of patients with normal systolic HBPM and no hypertensive treatment was 12 (52%) of 23 in the adrenalectomy group and none in the conservative management group. Serious adverse events occurred in eight (35%) of 23 participants in the adrenalectomy group and eight (31%) of 26 participants in the conservative management group. Three serious adverse events for three (13%) participants were related to the surgery (post-surgical wall pain and hypotension). INTERPRETATION:MACS associated with unilateral adrenal incidentalomas is responsible for secondary hypertension that can be safely improved by minimally-invasive adrenalectomy. FUNDING:French Ministry of Health and the German Research Foundation.

OBJECTIVE:Radiotherapy plays a relevant role in uncontrolled pituitary neuroendocrine tumors (PitNETs). Radiotherapy controls tumor progression in most cases, but not always. Prognostic factors for tumor progression after radiotherapy remain poorly defined. The aim was to evaluate tumor progression after radiotherapy, to identify risk factors, and to report management and outcomes in a cohort of PitNETs with uncontrolled progression. DESIGN:This was a retrospective, single-center, observational study. METHODS:In total, 123 consecutive patients who underwent radiotherapy for PitNETs and were followed at Cochin Hospital between 2000 and 2022 were included. Indication for radiotherapy was uncontrolled tumor progression (80%), adjuvant (9%), or uncontrolled secretion (11%). The median follow-up after radiotherapy was 10.0 years. RESULTS:Tumor progression after radiotherapy was observed in 28/123 (23%) patients. Higher risk of progression was associated with lactotroph and corticotroph tumor types (HR [95% CI] 12.0 [1.2-117.1] and 9.3 [1.3-69.6], respectively), male sex (3.7 [1.6-8.4]), and necrotic-hemorrhagic changes before radiotherapy on magnetic resonance imaging (3.1 [1.1-8.4]). Surgery, temozolomide, and re-irradiation were the most frequent treatments for the management of patients with tumor progression after radiotherapy, used in 18/28(64%), 16/28(57%), and 8/28(29%) cases, respectively. The most common complication of radiotherapy was the new onset of pituitary deficits, observed in 41% of cases; other complications, including radiation-induced neuroinflammation, cerebrovascular events, and second brain tumors, were rare. Three patients developed metastases, and 6 patients died because of tumor progression. CONCLUSIONS:Lactotroph and corticotroph PitNETs, in male patients, and/or with necrotic-hemorrhagic changes are at higher risk of progression after radiotherapy. Patients with progression after radiotherapy require additional heavy treatments with variable outcome.

In Cushing’s disease, the rate of endocrine remission after surgery reaches 80

Disclosure: F. Cioppi: None. T. Orioli: None. G. Cantini: None. T. Ercolino: None. F. Cioppi: None. G. Assié: None. A. Jouinot: None. A.A. Dedonno: None. M. Maggi: None. M. Benelli: None. L. Canu: None. G. Nesi: None. M. Luconi: None. Multiple endocrine neoplasia type 1 (MEN1) is a rare autosomal dominant inherited syndrome that predisposes to the development of multiple endocrine tumors including adrenal lesions. In the general population, adrenal masses occur with a 3% frequency, with a distribution of 80-85% of adrenal adenoma (ACA) or bilateral hyperplasia and 0.4-4% adrenocortical carcinoma (ACC). The occurrence of an adrenal incidentaloma dramatically increases in patients with MEN1 between 20-34%, where ACC cases raise up to 4.4-5.4%, according to the different cohorts, posing the problem of active surveillance with few predictors. In this MEN1 context, the possible evolution of a malignant from a benign lesion is particularly relevant to be clarified for the patient’s management. Malignant evolution from a benign form or the independent origin is still a matter of debate for adrenocortical tumors. Here, we report a unique case of a MEN1 patient operated for the rapid progression of a stable adrenal incidentaloma which was diagnosed as a large central ACC coexistent with a small peripheral ACA. Interestingly, the patient relapsed in 2-years in the diaphragmatic lodge. The availability of samples from the two coexistent masses and recurrence allowed a unique comparative pathological characterization associated with a deep genetic profiling by Whole Exome Sequencing (WES) of the three masses with the aim of assessing a collision hypothesis of the origin of the benign and malignant masses versus a sequence progression hypothesis, in a MEN1 presentation. Comparative immunohistochemistry confirmed the malignant features shared by the recurrence and ACC (marked positivity for SF1 and TP53, high Ki67, with disruption of the reticulum), while ACA was almost negative for Ki67, TP53, with intact reticulum. Expression profile signatures coherently classified ACA and ACC. WES analysis revealed a different mutational pattern between the benign and malignant forms with a total of 169 and 81 somatic Single Nucleotide Variants (SNVs) exclusively present in the benign (ACA) and in the malignant (ACC+recurrence) tissues, respectively. Among them, none SNV in known ACA-predisposing genes has been identified in the ACA sample. Conversely, a missense mutation in the exon 5 of TP53 (NM_000546.6:c.376T>G, p.Tyr126Asp) along with a NF1 donor splice site mutation (NM_001042492.3:c.4333-1G>C) were reported in both ACC and recurrence. TP53 and NF1 genes are well-known driver genes in ACC, and their alteration in the malignant forms suggests that they are mainly involved in the clonal evolution of the patient’s ACC. Interestingly, MEN1 locus showed Loss of Heterozygosity (LOH) in both ACC and recurrence but not in ACA. These findings support the hypothesis of an independent origin of the malignant and benign adrenocortical tumors, and remark the importance of tumor profiling by WES towards a better clinical management of these patients. Presentation: Monday, July 14, 2025

Adrenocortical carcinomas (ACC) are aggressive and resistant to medical treatment. This study reports a single-nucleus transcriptome atlas of steroid and microenvironment cells in 38 human normal adrenals and adrenocortical tumors. We identify intermediate-state cells between glomerulosa and fasciculata, a transition state in the centripetal trans-differentiation of normal steroid cells. In tumors, steroid cells show expression programs reflecting this zonation. Although ACC microenvironment is scarce, its signatures combine with those of steroid cells into ecotypes. A first ecotype combines cancer-associated fibroblasts, tumor-associated endothelial cells, with hypoxia and mitosis signatures in steroid cells. Another ecotype combines exhausted T cells, with fasciculata steroid signature. These ecotypes are associated with poor survival. Conversely, a third ecotype combines inflammatory macrophages, with reticularis steroid signature, and better outcome. These steroid/microenvironment cells interplays improve outcome predictions and may open therapeutic options in aggressive ACC, through immune microenvironment activation by modulating glucocorticoids/androgens balance.