Distinctive duodenal microbiomes and bile acid profiles in duodenal tumor patients revealed by prospective observational study.

The incidence of duodenal tumors (DTs) is increasing. However, the mechanisms underlying its development remain unclear. Environmental factors, including the microbiome and bile acids (BAs), are believed to influence tumor development. Therefore, we conducted a single-center, prospective, observational study to investigate the potential differences between patients with DTs and healthy controls (HCs) based on these factors. In addition, the BAs in the duodenal fluid were measured using liquid chromatography-tandem mass spectrometry. We recruited 41 patients and performed 16S rRNA-seq. There was no difference in the observed ASVs or PCoA plot of Bray-Curtis dissimilarity between the DTs and HCs. The lithocholic acid concentration was significantly lower in the DT group than in the control group. The ratio of CDCA to LCA was significantly higher in patients with DTs. No significant differences in microbiota were observed between DTs and HCs. In patients with DTs, the lithocholic acid concentration in duodenal was significantly lower than in HCs.

Frequent CDKN2B/P15 and DAPK1 methylation in duodenal follicular lymphoma is related to duodenal reactive lymphoid hyperplasia.

Duodenal type follicular lymphoma (DFL), a rare entity of follicular lymphoma (FL), is clinically indolent and is characterized by a low histological grade compared with nodal follicular lymphoma (NFL). Our previous reports revealed that DFL shares characteristics of both NFL and mucosa-associated lymphoid tissue (MALT) lymphoma in terms of clinical and biological aspects, suggesting its pathogenesis may involve antigenic stimulation. In contrast to NFL, the genomic methylation status of DFL is still challenging. Here, we determined the methylation profiles of DNAs from patients with DFL (n = 12), NFL (n = 10), duodenal reactive lymphoid hyperplasia (D-RLH) (n = 7), nodal reactive lymphoid hyperplasia (N-RLH) (n = 5), and duodenal samples from normal subjects (NDU) (n = 5) using methylation specific PCR of targets previously identified in MALT lymphoma (CDKN2B/P15, CDKN2A/P16, CDKN2C/P18, MGMT, hMLH-1, TP73, DAPK, HCAD). DAPK1 was frequently methylated in DFL (9/12; 75%), NFL (9/10; 90%), and D-RLH (5/7; 71%). CDKN2B/P15 sequences were methylated in six DFL samples and in only one NFL sample. Immunohistochemical analysis showed that p15 expression inversely correlated with methylation status. Genes encoding other cyclin-dependent kinase inhibitors (CDKN2A/P16, CDKN2C/P18) were not methylated in DFL samples. Methylation of the genes of interest was not detected in DNAs from D-RLH, except for DAPK1, and the difference in the extent of methylation between NDU and D-RLH was statistically significant (P = 0.013). Our results suggest that D-RLH serves as a reservoir for the development of DFL and that methylation of CDKN2B/P15 plays an important role in this process.

PIGA Mutations and Glycosylphosphatidylinositol Anchor Dysregulation in Polyposis-Associated Duodenal Tumorigenesis.

The pathogenesis of duodenal tumors in the inherited tumor syndromes familial adenomatous polyposis (FAP) and MUTYH-associated polyposis (MAP) is poorly understood. This study aimed to identify genes that are significantly mutated in these tumors and to explore the effects of these mutations. Whole exome and whole transcriptome sequencing identified recurrent somatic coding variants of phosphatidylinositol N-acetylglucosaminyltransferase subunit A (PIGA) in 19/70 (27%) FAP and MAP duodenal adenomas, and further confirmed the established driver roles for APC and KRAS. PIGA catalyzes the first step in glycosylphosphatidylinositol (GPI) anchor biosynthesis. Flow cytometry of PIGA-mutant adenoma-derived and CRISPR-edited duodenal organoids confirmed loss of GPI anchors in duodenal epithelial cells and transcriptional profiling of duodenal adenomas revealed transcriptional signatures associated with loss of PIGA. IMPLICATIONS: PIGA somatic mutation in duodenal tumors from patients with FAP and MAP and loss of membrane GPI-anchors may present new opportunities for understanding and intervention in duodenal tumorigenesis.

Inferred inactivation of the Cftr gene in the duodena of mice exposed to hexavalent chromium (Cr(VI)) in drinking water supports its tumor-suppressor status and implies its potential role in Cr(VI)-induced carcinogenesis of the small intestines.

Carcinogenicity of hexavalent chromium [Cr (VI)] has been supported by a number of epidemiological and animal studies; however, its carcinogenic mode of action is still incompletely understood. To identify mechanisms involved in cancer development, we analyzed gene expression data from duodena of mice exposed to Cr(VI) in drinking water. This analysis included (i) identification of upstream regulatory molecules that are likely responsible for the observed gene expression changes, (ii) identification of annotated gene expression data from public repositories that correlate with gene expression changes in duodena of Cr(VI)-exposed mice, and (iii) identification of hallmark and oncogenic signature gene sets relevant to these data. We identified the inactivated CFTR gene among the top scoring upstream regulators, and found positive correlations between the expression data from duodena of Cr(VI)-exposed mice and other datasets in public repositories associated with the inactivation of the CFTR gene. In addition, we found enrichment of signatures for oncogenic signaling, sustained cell proliferation, impaired apoptosis and tissue remodeling. Results of our computational study support the tumor-suppressor role of the CFTR gene. Furthermore, our results support human relevance of the Cr(VI)-mediated carcinogenesis observed in the small intestines of exposed mice and suggest possible groups that may be more vulnerable to the adverse outcomes associated with the inactivation of CFTR by hexavalent chromium or other agents. Lastly, our findings predict, for the first time, the role of CFTR inactivation in chemical carcinogenesis and expand the range of plausible mechanisms that may be operative in Cr(VI)-mediated carcinogenesis of intestinal and possibly other tissues.

Vascular endothelial growth factor-A is an Immunohistochemical biomarker for the efficacy of bevacizumab-containing chemotherapy for duodenal and jejunal adenocarcinoma.

BACKGROUND: The efficacy and safety of bevacizumab-containing chemotherapy for patients with metastatic duodenal and jejunal adenocarcinoma (mDJA) are unclear. The present study aimed to evaluate the efficacy of bevacizumab and to explore immunohistochemical markers that can predict the efficacy of bevacizumab for patients with mDJA. METHODS: This multicentre study included patients with histologically confirmed small bowel adenocarcinoma who received palliative chemotherapy from 2008 to 2017 at 15 hospitals. Immunostaining was performed for vascular endothelial growth factor-A (VEGF-A), TP53, Ki67, ß-catenin, CD10, MUC2, MUC5AC, MUC6, and mismatch repair proteins. RESULTS: A total of 74 patients were enrolled, including 65 patients with mDJA and 9 with metastatic ileal adenocarcinoma. Patients with mDJA who received platinum-based chemotherapy with bevacizumab as first-line treatment tended to have a longer progression-free survival and overall survival than those treated without bevacizumab (P = 0.075 and 0.077, respectively). Multivariate analysis extracted high VEGF-A expression as a factor prolonging progression-free survival (hazard ratio: 0.52, 95% confidence interval: 0.30-0.91). In mDJA patients with high VEGF-A expression, those who received platinum-based chemotherapy with bevacizumab as a first-line treatment had significantly longer progression-free survival and tended to have longer overall survival than those treated without bevacizumab (P = 0.025 and P = 0.056, respectively), whereas no differences were observed in mDJA patients with low VEGF-A expression. CONCLUSION: Immunohistochemical expression of VEGF-A is a potentially useful biomarker for predicting the efficacy of bevacizumab-containing chemotherapy for patients with mDJA.

CDH17+/CDX2+ Can be Helpful in Providing Support for Small Intestinal Origin Versus Pancreatic or Biliary Origin.

Because of the distinct and complex anatomy of the ampullary region, the exact origin of the periampullary tumors was often difficult to ascertain. In this study, we evaluated 78 patient samples, including 26 small intestinal adenocarcinomas, 35 pancreatic ductal adenocarcinomas, and 17 cholangiocarcinomas by immunohistochemical detection of cadherin-17 (CDH17), CDX2, CK20, and CK19 protein expression. The result showed that CDH17 and CDX2 expression was higher in small intestinal adenocarcinoma (73.1% and 65.4%) than in pancreatic (14.3% and 2.9%) and bile duct (41.2% and 23.5%) cancers, respectively. CK20 expression was low in 78 tumor tissues, but relatively high in small intestinal adenocarcinoma (42.3%). CK19 showed a strong positive expression in all 78 adenocarcinoma tissues. The CDH17-high/CDX2-high pattern was predominantly expressed in small intestinal cancer tissues (75%), whereas the CDH17-low/CDX2-low pattern was observed in pancreatic cancers (63.8%) and bile duct cancers (20.9%). The study concluded that CDH17-high/CDX2-high adenocarcinomas more likely originated from small intestine versus pancreas or bile duct, whereas CDH17-low/CDX2-low ones are more likely of pancreatic origin. The combined use of CDH17 and CDX2 could be helpful in providing support for the histologic origin of periampullary adenocarcinoma.

Prognostic implication of SOX2 expression in small intestinal adenocarcinoma.

The presence of KRAS mutation enhances the stem cell features of colorectal carcinoma cells containing mutant adenomatous polyposis coli (APC). However, their potential role in small intestinal adenocarcinoma remains elusive. Here, we aimed to investigate the clinical significance of cancer stem cell markers expression in the context of small intestinal adenocarcinoma with the KRAS genotype. SOX2, NANOG, and OCT4 expression were assessed by immunohistochemistry and digital image analysis, and their potential association with KRAS was further examined in 185 Korean patients with small intestinal adenocarcinomas, which were collected from 22 institutions in South Korea. Positive expression of SOX2, NANOG, and OCT4 was detected in 65 (35.1%), 94 (50.8%), and 82 (44.3%) of patients, respectively. Patients with high SOX2 (SOX2+) expression displayed worse overall survival compared to those with low SOX2 (SOX2-) expression (P < 0.001). Patients with SOX2+/mutant KRAS (KRASMT) (11.1 months) had significantly shorter overall survival than those with SOX2-/KRASWT (53.6 months) (P < 0.001). In multivariate analysis, SOX2+, distal location, high pT and pN categories, microsatellite stable, and absence of predisposing diseases were independent prognostic factors for worse overall survival. These results suggest that SOX2 expression has the potential to predict clinical outcomes in patients with small intestinal adenocarcinomas.

Cytokeratin-positive cells in the bone marrow from patients with pancreatic, periampullary malignancy and benign pancreatic disease show no prognostic information.

BACKGROUND: Pancreatic and periampullary carcinoma are aggressive tumours where preoperative assessment is challenging. Disseminated tumour cells (DTC) in the bone marrow (BM) are associated with impaired prognosis in a variety of epithelial cancers. In a cohort of patients with presumed resectable pancreatic and periampullary carcinoma, we evaluated the frequency and the potential prognostic impact of the preoperative presence of DTC, defined as cytokeratin-positive cells detected by immunocytochemistry (ICC). METHODS: Preoperative BM samples from 242 patients selected for surgical resection of presumed resectable pancreatic and periampullary carcinoma from 09/2009 to 12/2014, were analysed for presence of CK-positive cells by ICC. The median observation time was 21.5 months. Overall survival (OS) and disease-free survival (DFS) were calculated by Kaplan-Meier and Cox regression analysis. RESULTS: Successful resections of malignant tumours were performed in 179 of the cases, 30 patients resected had benign pancreatic disease based on postoperative histology, and 33 were deemed inoperable intraoperatively due to advanced disease. Overall survival for patients with resected carcinoma was 21.1 months (95% CI: 18.0-24.1), for those with benign disease OS was 101 months (95% CI: 69.4-132) and for those with advanced disease OS was 8.8 months (95% CI: 4.3-13.3). The proportion of patients with detected CK-positive cells was 6/168 (3.6%) in resected malignant cases, 2/31 (6.5%) in advanced disease and 4/29 (13.8%) in benign disease. The presence of CK-positive cells was not correlated to OS or DFS, neither in the entire cohort nor in the subgroup negative for circulating tumour cells (CTC). CONCLUSIONS: The results indicate that CK-positive cells may be present in both patients with malignant and benign diseases of the pancreas. Detection of CK-positive cells was not associated with differences in prognosis for the entire cohort or any of the subgroups analysed. TRIAL REGISTRATION: clinicaltrials.gov ( NCT01919151 ).

A Support Vector Machine Model Predicting the Risk of Duodenal Cancer in Patients with Familial Adenomatous Polyposis at the Transcript Levels.

OBJECTIVE: Familial adenomatous polyposis (FAP) is one major type of inherited duodenal cancer. The estimate of duodenal cancer risk in patients with FAP is critical for selecting the optimal treatment strategy. METHODS: Microarray datasets related with FAP were retrieved from the Gene Expression Omnibus (GEO) database. Differentially expressed genes were identified by FAP vs. normal samples and FAP and duodenal cancer vs. normal samples. Furthermore, functional enrichment analyses of these differentially expressed genes were performed. A support vector machine (SVM) was performed to train and validate cancer risk prediction model. RESULTS: A total of 196 differentially expressed genes were identified between FAP compared with normal samples. 177 similarly expressed genes were identified both in FAP and duodenal cancer, which were mainly enriched in pathways in cancer and metabolic-related pathway, indicating that these genes in patients with FAP could contribute to duodenal cancer. Among them, Cyclin D1, SDF-1, AXIN, and TCF were significantly upregulated in FAP tissues using qRT-PCR. Based on the 177 genes, an SVM model was constructed for prediction of the risk of cancer in patients with FAP. After validation, the model can accurately distinguish FAP patients with high risk from those with low risk for duodenal cancer. CONCLUSION: This study proposed a cancer risk prediction model based on an SVM at the transcript levels.

Influence of non-jaundice stage at diagnosis on clinicopathological features and long-term survival of patients with periampullary carcinomas.

The effect of non-jaundice stage at diagnosis on clinicopathological features and prognosis of patients with periampullary carcinomas (PACs) remains uncertain.The 504 patients who were pathologically diagnosed with PACs between 2012 and 2017 were retrospective analyzed. Kaplan-Meier method was used to estimate survival and log-rank tests were used for comparisons between groups.Patients were divided into the non-jaundice group and the jaundice group according to serum total bilirubin (3 mg/dL) at diagnosis. By comparison with the jaundice group, more patients of the non-jaundice group manifested abdominal pain with longer duration. The degree of deterioration of complete blood count, liver function and CA19-9 in the non-jaundice group was significantly lower (P < .001). The non-jaundice group had larger tumor size (P = .001), more duodenal carcinoma and pancreatic carcinoma (P < .001), lower resection rate (P = .001) and less pancreatic and perineural invasion (P = .017, P = .002). The I stage was significantly more common in the non-jaundice group (P < .001). The cumulative 5-year survival of the non-jaundice group was significantly higher (P = .032). Multivariate analysis for all patients demonstrated that CEA level, cell differentiation, chemotherapy, and recurrence were independent prognostic factors.Patients with PACs in a non-jaundice stage at diagnosis showed more favorable clinicopathological features and long-term survival than such patients with jaundice.

Postoperative serum metabolites of patients on a low carbohydrate ketogenic diet after pancreatectomy for pancreatobiliary cancer: a nontargeted metabolomics pilot study.

A ketogenic diet is a potential adjuvant cancer therapy that limits glucose availability to tumours while fuelling normal tissues with ketone bodies. We examined the effect of a low carbohydrate ketogenic diet (LCKD) (80% kcal from fat, ketogenic ratio 1.75:1, w/w) compared to a general hospital diet (GD) on serum metabolic profiles in patients (n = 18, ≥ 19 years old) who underwent pancreatectomy for pancreatobiliary cancer. Serum samples collected preoperatively (week 0) and after the dietary intervention (week 2) were analysed with a nontargeted metabolomics approach using liquid chromatography-tandem mass spectrometry. Serum ß-hydroxybutyrate and total ketone levels significantly increased after 2 weeks of LCKD compared to GD (p < 0.05). Principal component analysis score plots and orthogonal partial least squares discriminant analysis also showed significant differences between groups at week 2, with strong validation. In all, 240 metabolites differed between LCKD and GD. Pathways including glycerophospholipid and sphingolipid metabolisms were significantly enriched in the LCKD samples. LCKD decreased C22:1-ceramide levels, which are reported to be high in pancreatic cancer, while increasing lysophosphatidylcholine (18:2), uric acid, citrulline, and inosine levels, which are generally low in pancreatic cancer. Postoperative LCKD might beneficially modulate pancreatic cancer-related metabolites in patients with pancreatobiliary cancer.

Molecular alterations and PD-L1 expression in non-ampullary duodenal adenocarcinoma: Associations among clinicopathological, immunophenotypic and molecular features.

Non-ampullary duodenal adenocarcinoma (NADC) is extremely rare. Little is known about its clinicopathological and molecular features or its management. Herein we retrospectively analyzed the cases of 32 NADC patients, focusing on microsatellite instability (MSI), genetic mutations, CpG island methylator phenotype (CIMP), and immunostaining including mucin phenotype and PD-L1 expression. The incidence of MSI, KRAS/BRAF/GNAS mutations and CIMP was 51.6%, 34.4%/3.1%/6.5% and 28.1%, respectively. PD-L1 expression was seen in 34.4% of patients. No significant associations between clinicopathological features and KRAS/BRAF/GNAS genetic mutations or CIMP were found. Histologically non-well-differentiated-type NADCs and those in the 1st portion of the duodenum were significantly associated with later stages (stages III-IV) (P = 0.006 and P = 0.003, respectively). Gastric-phenotype NADCs were frequently observed in the 1st portion and in late-stage patients; their cancer cells more frequently expressed PD-L1. Histologically, the non-well-differentiated type was an independent predictor of PD-L1 expression in cancer cells (OR 25.05, P = 0.04) and immune cells (OR 44.14, P = 0.02). Only late-stage disease (HR 12.23, P = 0.01) was a prognostic factor for worse overall survival in a Cox proportional hazards regression model. Our observation of high proportions of MSI and PD-L1 expression may prompt the consideration of immune checkpoint inhibitors as a new treatment option for NADCs.

Can we classify ampullary tumours better? Clinical, pathological and molecular features. Results of an AGEO study.

BACKGROUND: Ampullary adenocarcinoma (AA) originates from either intestinal (INT) or pancreaticobiliary (PB) epithelium. Different prognostic factors of recurrence have been identified in previous studies. METHODS: In 91 AA patients of the AGEO retrospective multicentre cohort, we evaluated the centrally reviewed morphological classification, panel markers of Ang et al. including CK7, CK20, MUC1, MUC2 and CDX2, the 50-gene panel mutational analysis, and the clinicopathological AGEO prognostic score. RESULTS: Forty-three (47%) of the 91 tumours were Ang-INT, 29 (32%) were Ang-PB, 18 (20%) were ambiguous (Ang-AMB) and one could not be classified. Among these 90 tumours, 68.7% of INT tumours were Ang-INT and 78.2% of PB tumours were Ang-PB. MUC5AC expression was detected in 32.5% of the 86 evaluable cases. Among 71 tumours, KRAS, TP53, APC and PIK3CA were the most frequently mutated genes. The KRAS mutation was significantly more frequent in the PB subtype. In multivariate analysis, only AGEO prognostic score and tumour subtype were associated with relapse-free survival. Only AGEO prognostic score was associated with overall survival. CONCLUSIONS: Mutational analysis and MUC5AC expression provide no additional value in the prognostic evaluation of AA patients. Ang et al. classification and the AGEO prognostic score were confirmed as a strong prognosticator for disease recurrence.

Identification of marker genes and pathways specific to precancerous duodenal adenomas and early stage adenocarcinomas.

BACKGROUND: The mechanism behind the pathogenesis and carcinogenesis of these neoplasms is not fully understood. The objective of this study was to identify genetic markers and pathways specific to precancerous duodenal adenomas and early stage adenocarcinomas through gene expression analysis. METHODS: Gene expression profiling was performed in 4 pairs of duodenal adenoma/adenocarcinomas and corresponding matched normal tissue. Genes with consistent expression differences were identified and confirmed in 7 independent pairs. Gene set enrichment analysis (GSEA) was performed to characterize gene expression profiles of duodenal adenoma/adenocarcinomas, together with immunohistochemical staining of candidate oncogenic genes. RESULTS: 626 probes consistently demonstrated over a twofold expression difference between tumor-normal pairs. Reverse transcriptase polymerase chain reaction of genes with the most prominent difference in expression between tumors and normal mucosa (KLK7, KLK6, CEMIP, MMP7, KRT17, LGR5, G6PC, S100G, APOA1) validated the results of gene expression analysis. GSEA demonstrated a strong association between duodenal adenoma/adenocarcinomas with colorectal adenomas (p < 10-5) and gene expression patterns seen after APC gene knockout (p < 10-5), suggesting that the Wnt/ß-catenin pathway plays a crucial role in the carcinogenesis of these neoplasms. Immunohistochemical staining of an independent group of duodenal adenomas confirmed over-accumulation of ß-catenin in 80.0% (16/20). CONCLUSIONS: Precancerous duodenal adenomas and early stage adenocarcinomas demonstrate gene expression characteristics with a strong resemblance to colorectal adenomas. The results of this study strongly suggest that upregulation of the Wnt/ß-catenin pathway is the major factor involved in the initial stages of the carcinogenesis of duodenal adenocarcinomas.

Expression of Gastric Markers Is Associated with Malignant Potential of Nonampullary Duodenal Adenocarcinoma.

BACKGROUND: Sporadic nonampullary duodenal epithelial tumors (NADETs) are uncommon, and thus their clinicopathological features have not been fully assessed. AIMS: In this study, we have analyzed a series of early sporadic NADETs, focusing on various immunohistological features. METHODS: We conducted a multicenter retrospective analysis of 68 patients with endoscopically resected sporadic NADETs. Associations between immunohistological features and clinicopathological features were statistically analyzed. RESULTS: The 68 patients consisted of 46 men (68%) and 22 women (32%) with a mean age of 60.7 ± 12.2 years (range 37-85 years). The 68 tumors were composed of 39 adenomas (57%) and 29 early-stage adenocarcinomas (43%). Duodenal adenocarcinomas were larger in size than adenomas and had papillary architecture in their pathological diagnosis with statistical significance. Duodenal adenocarcinomas also demonstrated a significantly higher expression of gastric markers (MUC5AC and MUC6) and a higher MIB-1 index. Duodenal adenomas were contrastively apt to express intestinal markers (MUC2, CDX1 and CDX2). Of the 68 cases analyzed, there were only 3 tumors positive for p53 staining, all of which were adenocarcinoma. When 7 submucosal invasive cancers and 21 intramucosal cancers were compared, submucosal invasion was positively associated with expression of MUC5AC. Also, submucosal invasion showed strong association with double-positivity of MUC5AC and MUC6. CONCLUSIONS: Our results indicate that immunohistochemical evaluation is useful for predicting malignant potential of NADETs, especially focusing on the expression of gastrointestinal markers.

Sarcopenia and myosteatosis are accompanied by distinct biological profiles in patients with pancreatic and periampullary adenocarcinomas.

INTRODUCTION: Pancreatic and periampullary adenocarcinomas are associated with abnormal body composition visible on CT scans, including low muscle mass (sarcopenia) and low muscle radiodensity due to fat infiltration in muscle (myosteatosis). The biological and clinical correlates to these features are poorly understood. METHODS: Clinical characteristics and outcomes were studied in 123 patients who underwent pancreaticoduodenectomy for pancreatic or non-pancreatic periampullary adenocarcinoma and who had available preoperative CT scans. In a subgroup of patients with pancreatic cancer (n = 29), rectus abdominus muscle mRNA expression was determined by cDNA microarray and in another subgroup (n = 29) 1H-NMR spectroscopy and gas chromatography-mass spectrometry were used to characterize the serum metabolome. RESULTS: Muscle mass and radiodensity were not significantly correlated. Distinct groups were identified: sarcopenia (40.7%), myosteatosis (25.2%), both (11.4%). Fat distribution differed in these groups; sarcopenia associated with lower subcutaneous adipose tissue (P<0.0001) and myosteatosis associated with greater visceral adipose tissue (P<0.0001). Sarcopenia, myosteatosis and their combined presence associated with shorter survival, Log Rank P = 0.005, P = 0.06, and P = 0.002, respectively. In muscle, transcriptomic analysis suggested increased inflammation and decreased growth in sarcopenia and disrupted oxidative phosphorylation and lipid accumulation in myosteatosis. In the circulating metabolome, metabolites consistent with muscle catabolism associated with sarcopenia. Metabolites consistent with disordered carbohydrate metabolism were identified in both sarcopenia and myosteatosis. DISCUSSION: Muscle phenotypes differ clinically and biologically. Because these muscle phenotypes are linked to poor survival, it will be imperative to delineate their pathophysiologic mechanisms, including whether they are driven by variable tumor biology or host response.

Ectopic adrenocorticotropic hormone syndrome in a case of duodenal neuroendocrine tumor presenting with liver metastasis.

Ectopic adrenocorticotropic hormone (ACTH) syndrome is an uncommon disorder and comprises about 15% of all patients with Cushing's syndrome (CS). Duodenal carcinoids are rare, indolent tumors usually associated with a benign progression. We hereby report a rare case of CS resulting from ectopic ACTH secretion from a duodenal neuroendocrine tumor (NET) presenting with liver metastasis. A 37-year-old female presented with abdominal discomfort and dyspepsia of 1-month duration. Ultrasound abdomen suggested a well-defined hypoechoic lesion in the left lobe of the liver, suggestive of neoplasia. On clinical examination, she had Cushingoid features and persistent hypokalemia. Midnight ACTH and cortisol levels were grossly elevated at 1027 pg/ml (n < 46 pg/ml) and 87.56 µg/dl (n < 7.5 µg/ml), respectively. Both overnight and high-dose dexamethasone suppression test confirmed nonsuppressed cortisol levels - 86.04 and 84.42 µg/dl (n < 1.8 µg/ml), respectively. Magnetic resonance imaging brain showed a structurally normal pituitary gland. Computed tomography scan of the abdomen revealed hepatic lesion with bilateral adrenal enlargement. A diagnosis of ectopic ACTH-dependent CS was made. Intraoperatively, a duodenal lesion of 0.5 cm × 0.5 cm was identified alongside an 8 cm × 6 cm exophytic lesion in segment IV of the liver. Frozen section of the duodenal lesion was positive for NET. She underwent a Whipple's surgery, cholecystectomy, and left hepatic lobectomy. Postoperatively, she showed clinical and biochemical remission. Herewith, we report the third case of duodenal carcinoid tumor presenting as ectopic ACTH syndrome and the first with liver metastasis.