[Interpretation of the 5th edition WHO classification of adrenal cortical tumors].

Non-neoplastic lesions were added in the 5th edition WHO classification of adrenal cortical tumor based on the recent update, including adrenal rests, adrenal cysts, congenital adrenal hyperplasia and adrenocortical nodular disease. A range of tumor concepts were updated or refined based on tumor cell origin, histopathology, oncology and molecular biology. The most significant nomenclature change in the field of adrenal cortical pathology involves the refined classification of adrenal cortical nodular disease, which now includes sporadic nodular adrenocortical disease, bilateral micronodular adrenal cortical disease, and bilateral macronodular adrenal cortical disease. The 5th edition WHO classification endorses the nomenclature of the HISTALDO classification to help the classification of aldosterone producing adrenal cortical lesions, which uses CYP11B2 immunohistochemistry to identify functional sites of aldosterone production. The 5th edition WHO classification does not change the Weiss and Lin-Weiss-Bisceglia histopathologic criteria for diagnosing adrenal cortical carcinomas, and underscores the diagnostic and prognostic impact of angioinvasion in these tumors. Reticulin algorithm and Helsinki scoring system were added to assist the differential diagnosis of adrenal cortical neoplasms in adults. Pediatric adrenal cortical neoplasms are assessed using the Wieneke system. The 5th edition WHO classification places an emphasis on an accurate assessment of tumor proliferation rate using both the mitotic count (mitoses per 10 mm2) and Ki-67 labeling index which play an essential role in the dynamic risk stratification of affected patients. This review highlights advances in knowledge of histological features, ancillary studies, and associated genetic findings that increase the understanding of the adrenal cortex pathologies in the 5th edition WHO classification.

Interpretation of the 5th edition WHO classification of adrenal cortical tumors / 中华病理学杂志

Non-neoplastic lesions were added in the 5th edition WHO classification of adrenal cortical tumor based on the recent update, including adrenal rests, adrenal cysts, congenital adrenal hyperplasia and adrenocortical nodular disease. A range of tumor concepts were updated or refined based on tumor cell origin, histopathology, oncology and molecular biology. The most significant nomenclature change in the field of adrenal cortical pathology involves the refined classification of adrenal cortical nodular disease, which now includes sporadic nodular adrenocortical disease, bilateral micronodular adrenal cortical disease, and bilateral macronodular adrenal cortical disease. The 5th edition WHO classification endorses the nomenclature of the HISTALDO classification to help the classification of aldosterone producing adrenal cortical lesions, which uses CYP11B2 immunohistochemistry to identify functional sites of aldosterone production. The 5th edition WHO classification does not change the Weiss and Lin-Weiss-Bisceglia histopathologic criteria for diagnosing adrenal cortical carcinomas, and underscores the diagnostic and prognostic impact of angioinvasion in these tumors. Reticulin algorithm and Helsinki scoring system were added to assist the differential diagnosis of adrenal cortical neoplasms in adults. Pediatric adrenal cortical neoplasms are assessed using the Wieneke system. The 5th edition WHO classification places an emphasis on an accurate assessment of tumor proliferation rate using both the mitotic count (mitoses per 10 mm2) and Ki-67 labeling index which play an essential role in the dynamic risk stratification of affected patients. This review highlights advances in knowledge of histological features, ancillary studies, and associated genetic findings that increase the understanding of the adrenal cortex pathologies in the 5th edition WHO classification.

Metallothionein protein and minichromosome maintenance protein-2 expression in adrenocortical tumors.

AIM: Some resected adrenal-confined adrenocortical carcinomas metastasize and others not. The present study was designed to evaluate the expression of metallothionein protein (MT) and minichromosome maintenance protein-2 (MCM2) in adrenocortical carcinomas and adrenocortical adenomas, and to test the correlation between this and adrenocortical carcinoma aggressiveness. MATERIALS AND METHODS: The study comprised 14 patients operated on for adrenocortical carcinoma, 15 operated on for adrenocortical adenoma and 2 with normal adrenals. Hematoxylin-eosin staining was used for histological evaluation under light microscopy, and sequential sections were used for MCM2 and MT staining. RESULTS: In normal adrenals, positive staining was weak for MT and zero for MCM2. Rates of positive staining for MT and MCM2 were significantly higher in adrenocortical carcinomas than in adrenocortical adenomas (P=0.008 and P<0.001, respectively). In adrenocortical carcinomas, a significant positive correlation was found between MCM2 staining and Weiss revisited score (P=0.022) but not for Weiss score, and a significant positive correlation was found between MCM2 and mitotic rate on histology (P=0.033). MCM2 but not MT staining was also shown to correlate significantly with stage IV carcinoma (P=0.008 and P=0.165, respectively). CONCLUSION: MCM2 and MT are overexpressed in adrenocortical carcinoma, and MCM2 expression correlates significantly with metastatic disease.

Diagnostic and prognostic utility of SF1, IGF2 and p57 immunoexpression in pediatric adrenal cortical tumors.

BACKGROUND: Adrenocortical tumors (ACT) are uncommon in the pediatric age group. Using the standard Weiss criteria in pediatric tumors leads to overdiagnosis. This has led to the development of newer systems such as Weineke criteria. Ki67 labeling index aids in differentiating adenomas from carcinomas. We aim to evaluate the diagnostic and prognostic role of Ki67 labeling index, along with immunoexpression of steroidogenic factor-1, insulin like growth factor 2 and p57, in pediatric ACTs diagnosed using Weineke criteria. METHODS: We have studied 25 cases of pediatric ACTs. Immunohistochemical staining for Ki67, SF-1, IGF2 and p57 was done in all cases and the result was correlated with the morphological diagnosis using the Weineke criteria. RESULTS: Ki67 labeling index showed complete concordance with the morphological diagnosis. SF-1 and IGF2 showed similar correlation with the diagnosis, with IGF-2 proving to be a more specific marker. Increased Ki67, SF-1 and IGF2 immunostaining also correlated with worse survival. p57 was more specific in determining benign status of a tumor. CONCLUSION: SF-1 and IGF2 are highly sensitive markers of malignancy in pediatric ACTs and can be used in combination with Ki67 expression for optimal diagnostic and prognostic assessment of pediatric ACTs. TYPE OF STUDY: Prognosis study. LEVEL OF EVIDENCE: Level II.

[Clinicopathologic features of myxoid adrenocortical adenomas].

Objective: To study the clinicopathologic characteristics, immunophenotype, pathologic diagnosis and differential diagnosis of myxoid adrenocortical adenomas. Methods: The clinical data, histological features and immunohistochemical results of 4 cases of myxoid adrenocortical adenomas were analyzed, which were collected from January 2014 to December 2016 at Guangdong General Hospital, with review of literature. Results: Four cases of myxoid adrenocortical adenomas were presented. The patients ages ranged from 26 to 45 years (mean =35 years). Microscopically, it showed a typical morphology, characterized by small-sized tumor cell cords or pseudo-glands embedded in an abundant extracellular myxoid matrix. Immunohistochemical staining showed tumor cells were strongly positive for Melan A, vimentin and focally for α-inhibin, one case showed strong and diffuse positivity for CAM5.2, and two cases showed diffuse positivity for synaptophysin, while negative for CgA, S-100 protein, epithelial antigen, CK7, CK20 and CKpan. Conclusions: Myxoid adrenocortical adenomas are extremely rare, which may cause confusion with metastatic well-differentiated neuroendocrine tumours, sex cord-stromal tumoursor metanephric adenoma. Recognition of this entity would be beneficial for pathologists to avoid misdiagnosis, and unnecessary treatment.

Diagnostic and Prognostic Biomarkers of Adrenal Cortical Carcinoma.

The diagnosis of low-grade adrenal cortical carcinoma (ACC) confined to the adrenal gland can be challenging. Although there are diagnostic and prognostic molecular tests for ACC, they remain largely unutilized. We examined the diagnostic and prognostic value of altered reticulin framework and the immunoprofile of biomarkers including IGF-2, proteins involved in cell proliferation and mitotic spindle regulation (Ki67, p53, BUB1B, HURP, NEK2), DNA damage repair (PBK, γ-H2AX), telomere regulation (DAX, ATRX), wnt-signaling pathway (beta-catenin) and PI3K signaling pathway (PTEN, phospho-mTOR) in a tissue microarray of 50 adenomas and 43 carcinomas that were characterized for angioinvasion as defined by strict criteria, Weiss score, and mitotic rate-based tumor grade. IGF-2 and proteins involved in cell proliferation and mitotic spindle regulation (Ki67, p53, BUB1B, HURP, NEK2), DNA damage proteins (PBK, γ-H2AX), regulators of telomeres (DAXX, ATRX), and beta-catenin revealed characteristic expression profiles enabling the distinction of carcinomas from adenomas. Not all biomarkers were informative in all carcinomas. IGF-2 was the most useful biomarker of malignancy irrespective of tumor grade and cytomorphologic features, as juxtanuclear Golgi-pattern IGF-2 reactivity optimized for high specificity was identified in up to 80% of carcinomas and in no adenomas. Loss rather than qualitative alterations of the reticulin framework yielded statistical difference between carcinoma and adenoma. Angioinvasion defined as tumor cells invading through a vessel wall and intravascular tumor cells admixed with thrombus proved to be the best prognostic parameter, predicting adverse outcome in the entire cohort as well as within low-grade ACCs. Low mitotic tumor grade, Weiss score, global loss of DAXX expression, and high phospho-mTOR expression correlated with disease-free survival, but Weiss score and biomarkers failed to predict adverse outcome in low-grade disease. Our results underscore the importance of careful morphologic assessment coupled with ancillary diagnostic and prognostic biomarkers of ACC.

ERCC1 as predictive biomarker to platinum-based chemotherapy in adrenocortical carcinomas.

OBJECTIVE: Platinum-based chemotherapy (PBC) is the most effective cytotoxic treatment for advanced adrenocortical carcinoma (ACC). Excision repair cross complementing group 1 (ERCC1) plays a critical role in the repair of platinum-induced DNA damage. Two studies investigating the role of ERCC1 immunostaining as a predictive marker for the response to PBC in ACC had reported conflicting results. Both studies used the ERCC1-antibody clone 8F1 that later turned out to be not specific. The aim of this study was to evaluate the predictive role of ERCC1 with a new specific antibody in a larger series of ACC. DESIGN AND METHODS: 146 ACC patients with available FFPE slides were investigated. All patients underwent PBC (median cycles = 6), including cisplatin (n = 131) or carboplatin (n = 15), in most cases combined with etoposide (n = 144), doxorubicin (n = 131) and mitotane (n = 131). Immunostaining was performed with the novel ERCC1-antibody clone 4F9. The relationship between ERCC1 expression and clinicopathological parameters, as well as best objective response to therapy and progression-free survival (PFS) during PBC was evaluated. RESULTS: High ERCC1 expression was observed in 66% of ACC samples. During PBC, 43 patients experienced objective response (29.5%), 49 stable disease (33.6%), 8 mixed response (5.5%) and 46 progressive disease (31.5%) without any relationship with the ERCC1 immunostaining. No significant correlation was also found between ERCC1 expression and progression-free survival (median 6.5 vs 6 months, P = 0.33, HR = 1.23, 95% CI = 0.82-2.0). CONCLUSION: ERCC1 expression is not directly associated with sensitivity to PBC in ACC. Thus, other predictive biomarkers are required to support treatment decisions in patients with ACC.

Oncocytic Adreno Cortical Tumors: Pathological Features of 16 Cases and Review of the Literature.

Oncocytic neoplasms of the adrenal gland are extremely rare tumors. These tumors differ from their nononcocytic counterparts in some respects. The aim of this study was to review and discuss the clinical, histological, and immunohistochemical features of as well as the prognosis for these rare tumors. In total, 16 cases diagnosed as adrenocortical oncocytic neoplasms between January 2011 and December 2016 were included in the study. The demographic data, gross characteristics, histological data, and immunohistochemical data (Chromogranin-A, Synaptophysin, α-Inhibin, Melan-A, Ki67, PHH3) were reevaluated. The follow-up data for these patients were added in January 2017. Of the 16 cases, 12 were adrenocortical adenoma, 1 was borderline adrenocortical tumor, and 3 were adrenocortical carcinoma. The tumors equally affected both genders. The tumors were not generally large. Tumor cells had pleomorphic nuclei in ten cases, but it was more obvious in one case. The mitotic figure count was low in most tumors. Atypical mitosis and necrosis were observed in three and four tumors, respectively. None of cases included sinusoidal invasion, vascular invasion, or capsular invasion. We detected the expression of at least one specific marker (e.g., Melan-A, Inhibin-α) of the adrenal cortex in all tumors. None of the tumors were immunoreactive for Chromogranin-A. Ki-67 proliferation index was lower than 5% in all cases except three oncocytic carcinomas. In two cases, PHH3 positivity was not seen, while it was lower than 3 of 10 high-powered fields in ten cases and higher in 4 cases. All patients were alive and disease free except for two patients with adrenocortical carcinoma. In conclusion, determining the clinical, histological, and immunohistochemical characteristics of these extremely rare tumors can provide important information for early diagnosis, treatment, and follow-up of these cases.

Myxoid Adrenocortical Adenoma: A report of two cases and literature review.

Myxoid adrenocortical adenomas are uncommon. There were only 61 cases reports documented, and the tumors are tended to be misdiagnosed in virtue of being rare and distinctive histological features. Recently we encountered two myxoid adrenocortical adenoma cases of a 31-year-old Chinese woman and a 45-year-old Chinese man. The patients did not receive further treatment after surgery and were still alive after following up for 20 months. Myxoid adrenocortical adenomas is extremely rare. Recognition of this entity would be beneficial for pathologists to avoid msidiagnosis, and unnecessary treatment.

Analysis of histological and immunohistochemical patterns of benign and malignant adrenocortical tumors by computerized morphometry.

Diagnosis of benign and purely localized malignant adrenocortical lesions is still a complex issue. Moreover, histology-based diagnosis may suffer of a moment of subjectivity due to inter- and intra-individual variations. The aim of the present study was to assess, by computerized morphometry, the morphological features in benign and malignant adrenocortical neoplasms. Eleven adrenocortical adenomas (ACA) were compared with 18 adrenocortical cancers (ACC). All specimens were stained with H&E, cellular proliferation marker Ki-67 and reticulin. We generated a morphometric model based on the analysis of volume fractions occupied by Ki-67 positive and negative cells (nuclei and cytoplasm), vascular and inflammatory compartment; we also analyzed the surface fraction occupied by reticulin. We compared the quantitative data of Ki-67 obtained by morphometry with the quantification resulting from pathologist's visual reading. The volume fraction of Ki-67 positive cells in ACCs was higher than in ACAs. The volume fraction of nuclei in unit volume and the nuclear/cytoplasmic ratio in both Ki-67 negative cells and Ki-67 positive cells were prominent in ACCs. The surface fraction of reticulin was considerably lower in ACCs. Our computerized morphometric model is simple, reproducible and can be used by the pathologist in the histological workup of adrenocortical tumors to achieve precise and reader-independent quantification of several morphological characteristics of adrenocortical tumors.

Validation of the prognostic role of the "Helsinki Score" in 225 cases of adrenocortical carcinoma.

Adrenocortical carcinoma patient prognosis is extremely variable and poorly predictable. The newly introduced Helsinki Score is the first so far proposed diagnostic and prognostic system based on the combined evaluation of morphological (mitoses and necrosis) and immunohistochemical (Ki-67) parameters. The aim of the study was to validate the prognostic role of the Helsinki Score for adrenocortical carcinoma characterization. Thus, 225 adrenocortical carcinomas were reclassified using the Weiss Score and the Helsinki Score (3× mitotic count + 5 × necrosis + Ki-67 index). At univariate analysis, statistically significant prognostic values were observed at the log-rank test for mitotic count (cutoff values: <6 and ≥55; P<.0001), Ki-67 (cutoff values: <20 and ≥50; P<.0001), Weiss Score (cutoff values: <5 and ≥8; P<.0001), Helsinki Score (cutoff values: <13 and ≥19; P<.0001), histological variant (conventional versus oncocytic; P=.009), necrosis (P=.001), and stage (P=.005). Cox multivariate analysis using a backward stepwise selection method retained only Helsinki Score and Weiss Score as predictors of poor prognosis (P<.0001 and P=.0005, respectively). Helsinki Score (with a threshold of 28.5 points; area under the curve [AUC]=0.729, 95% confidence interval=0.66-0.79) and Ki-67 (with a threshold of 20.5%; AUC=0.727, 95% confidence interval=0.66-0.79) showed the best and equivalent AUCs predicting disease-related deaths determined using receiver operating characteristic statistics. In conclusion, the Helsinki Score is a valuable system to predict prognosis in adrenocortical carcinoma, outperforming the currently established prognostic parameters.

Sarcomatoid adrenocortical carcinoma: a comprehensive pathological, immunohistochemical, and targeted next-generation sequencing analysis.

Adrenocortical carcinomas (ACCs) with sarcomatous areas represent an extremely rare type of highly aggressive malignancy of unknown molecular pathogenesis. The current study was planned to gain insight into its molecular genetics using a targeted next-generation sequencing approach and to explore the status of epithelial-mesenchymal transition (EMT)-associated markers (E-/P-/N-cadherins, MMP-2/-9 and caveolin-1), downstream transcriptional regulators of EMT-related signaling pathways (ZEB-1/-2, Slug), stem cell factors (Oct3/4, LIN28, SOX2, SO17, NANOG, CD133, nestin), and markers of adrenocortical origin/tumorigenesis (SF-1, ß-catenin, p53) in phenotypically diverse tumor components of 6 cases. Thirteen pathogenic variants of ACC-associated TP53 and CTNNB1 genes were detected in epithelial and/or nonepithelial components in 4 out of 6 tumors. Three cases had identical mutations in distinct components, 1 of which contained TP53/CTNNB1 in 3 out of 5 components, whereas 1 harbored a single TP53 mutation only in the nonepithelial component. By immunohistochemistry, SF-1 and E-/P-/N-cadherins were found positive only in the epithelial component of all cases, whereas the nonepithelial components were mainly enriched for nestin, ZEB-1, and MMP-2/-9. ß-Catenin demonstrated an aberrant nuclear localization in the sarcomatoid component of 5 cases, whereas p53 was strongly positive in nonepithelial constituent in 4 of 6 cases. In summary, we have shown that Wnt/ß-catenin signaling pathway dysregulation and mutational inactivation of TP53 are common genetic events in sarcomatoid ACCs, a subset of which being monoclonal in origin. These tumors are enriched for EMT-related markers and stem cell factors, potentially conferring a poor prognosis, which might be exploited as novel therapeutic targets.

Comparison of the methods for measuring the Ki-67 labeling index in adrenocortical carcinoma: manual versus digital image analysis.

Adrenocortical carcinoma (ACC) is a rare, highly malignant neoplasm harboring marked histologic heterogeneity. The Ki-67 labeling index (LI) is one of the most effective diagnostic and prognostic markers in ACC. However, its assessment has by no means been standardized. Therefore, in this study, we analyzed the Ki-67 LI in 18 ACC cases both by seven pathologists using microscopes (MA; manual analysis) and with digital image analysis (DIA) and also compared the Ki-67 LI obtained by selecting "hot spots" and formulating the "average" reading of the whole tumor specimen. In addition, we performed statistical analysis of the association between Ki-67 LI and the clinical and pathologic features of individual cases. The DIA was significantly correlated with MA in hot spots but not in the average fields. The Ki-67 LI in hot spots was significantly and consistently higher than that in average areas by both MA and DIA, indicating intratumoral heterogeneity. The Ki-67 LI was significantly correlated with the Weiss criteria (eosinophilic cytoplasm, nuclear atypia, atypical mitoses, and sinusoidal invasion) by any mode of evaluation. The clinical outcome was significantly better in the patients with a Ki-67 < 10% than in those with a Ki-67 > 10% by MA in hot spots. The Ki-67 LI in hot spots measured by MA best reflected the clinical and pathologic features of ACC. Employment of DIA to obtain the Ki-67 LI in ACC requires further improvement, including correction of its overestimation of the value by counting non-tumorous cells and nuclear segmentation in areas of high cell density.

Prostate-Specific Membrane Antigen Is a Potential Antiangiogenic Target in Adrenocortical Carcinoma.

CONTEXT: Adrenocortical carcinoma (ACC) is a rare tumor type with a poor prognosis and few therapeutic options. OBJECTIVE: Assess prostate-specific membrane antigen (PSMA) expression as a potential novel therapeutic target for ACC. DESIGN: Expression of PSMA was evaluated in benign and malignant adrenal tumors and 1 patient with metastatic ACC. SETTING: This study took place at a tertiary referral center. PATIENTS: Fifty adrenal samples were evaluated, including 16 normal adrenal glands, 16 adrenocortical adenomas, 15 primary ACC, and 3 ACC metastases. MAIN OUTCOME MEASURES: Demographics, PSMA expression levels via real-time quantitative polymerase chain reaction and immunohistochemistry and whole-body positron emission tomography-computed tomography standardized uptake values for 1 patient. RESULTS: qPCR demonstrated an elevated level of PSMA in ACC relative to all benign tissues (P < .05). Immunohistochemistry localized PSMA expression to the neovasculature of ACC and confirmed overexpression of PSMA in ACC relative to benign tissues both in intensity and percentage of vessels stained (78% of ACC, 0% of normal adrenal, and 3.27% of adenoma-associated neovasculature; P < .001). Those with more than 25% PSMA-positive vessels were 33 times more likely to be malignant than benign (odds ratio, P < .001). Whole-body positron emission tomography-computed tomography imaging showed targeting of anti-PSMA Zr89-J591 to 5/5 of the patient's multiple lung masses with an average measurement of 3.49 ± 1.86 cm and a standardized uptake value of 1.4 ± 0.65 relative to blood pool at 0.8 standardized uptake value. CONCLUSIONS: PSMA is significantly overexpressed in ACC neovasculature when compared with normal and benign adrenal tumors. PSMA expression can be used to image ACC metastases in vivo and may be considered as a potential diagnostic and therapeutic target in ACC.

Metabolic reprogramming: a new relevant pathway in adult adrenocortical tumors.

Adrenocortical carcinomas (ACCs) are complex neoplasias that may present unexpected clinical behavior, being imperative to identify new biological markers that can predict patient prognosis and provide new therapeutic options. The main aim of the present study was to evaluate the prognostic value of metabolism-related key proteins in adrenocortical carcinoma. The immunohistochemical expression of MCT1, MCT2, MCT4, CD147, CD44, GLUT1 and CAIX was evaluated in a series of 154 adult patients with adrenocortical neoplasia and associated with patients' clinicopathological parameters. A significant increase in was found for membranous expression of MCT4, GLUT1 and CAIX in carcinomas, when compared to adenomas. Importantly MCT1, GLUT1 and CAIX expressions were significantly associated with poor prognostic variables, including high nuclear grade, high mitotic index, advanced tumor staging, presence of metastasis, as well as shorter overall and disease free survival. In opposition, MCT2 membranous expression was associated with favorable prognostic parameters. Importantly, cytoplasmic expression of CD147 was identified as an independent predictor of longer overall survival and cytoplasmic expression of CAIX as an independent predictor of longer disease-free survival. We provide evidence for a metabolic reprogramming in adrenocortical malignant tumors towards the hyperglycolytic and acid-resistant phenotype, which was associated with poor prognosis.

Dissecting Morphological and Molecular Heterogeneity in Adrenocortical Carcinoma.

Adrenocortical carcinoma is generally considered a single entity by pathologists and clinicians. Nevertheless, the knowledge cumulated along the last decade on the pathological characterization, the clinical outcome and the molecular pathogenesis of adrenocortical carcinoma demonstrate that one of the most relevant emerging issues is related to its heterogeneity. Three major morphological variants have been described (oncocytic, myxoid and sarcomatoid) but are not included in the current WHO classification, yet. Moreover, even "conventional" adrenocortical carcinomas have a high degree of morphological heterogeneity as well as different mitotic/proliferative capacity, either among different cases or within individual lesions. Furthermore, immunohistochemical and molecular studies, based on a wide set of different methodologies, identified novel biomarkers in adrenocortical carcinoma of diagnostic and prognostic relevance, which claimed again the concept that this tumor type represents an heterogeneous group of neoplasms which cannot be considered a unique entity. The integration between morphology, immunophenotype and molecular data is expected in the next years to build a novel concept of adrenocortical carcinoma classification into specific subgroups, as it is currently approached for other types of neoplasms such as breast or lung cancer, which are not merely descriptive, but also characterized by a specific biological and clinical behavior.

Oncocytic adrenocortical carcinoma--a rare pathological variant.

Oncocytic adrenocortical carcinoma is a rare histopathological variant of adrenocortical carcinoma with very few instances reported in the literature to date. With progressive research, new insights have emerged in the molecular profiling of these tumours. This advancement has led to more clarity in reporting of this tumour. We report a case of oncocytic adrenocortical carcinoma with its attending clinical presentation, immunohistochemical profiling and characteristic electron microscopy findings.

2D-DIGE proteomic analysis identifies new potential therapeutic targets for adrenocortical carcinoma.

Adrenocortical carcinoma (ACC) is a rare aggressive tumor with poor prognosis when metastatic at diagnosis. The tumor biology is still mostly unclear, justifying the limited specificity and efficacy of the anti-cancer drugs currently available. This study reports the first proteomic analysis of ACC by using two-dimensional-differential-in-gel-electrophoresis (2D-DIGE) to evaluate a differential protein expression profile between adrenocortical carcinoma and normal adrenal. Mass spectrometry, associated with 2D-DIGE analysis of carcinomas and normal adrenals, identified 22 proteins in 27 differentially expressed 2D spots, mostly overexpressed in ACC. Gene ontology analysis revealed that most of the proteins concurs towards a metabolic shift, called the Warburg effect, in adrenocortical cancer. The differential expression was validated by Western blot for Aldehyde-dehydrogenase-6-A1,Transferrin, Fascin-1,Lamin A/C,Adenylate-cyclase-associated-protein-1 and Ferredoxin-reductase. Moreover, immunohistochemistry performed on paraffin-embedded ACC and normal adrenal specimens confirmed marked positive staining for all 6 proteins diffusely expressed by neoplastic cells, compared with normal adrenal cortex.In conclusion, our preliminary findings reveal a different proteomic profile in adrenocortical carcinoma compared with normal adrenal cortex characterized by overexpression of mainly metabolic enzymes, thus suggesting the Warburg effect also occurs in ACC. These proteins may represent promising novel ACC biomarkers and potential therapeutic targets if validated in larger cohorts of patients.