Spatial profiling reveals tissue-specific neuro-immune interactions in gastroenteropancreatic neuroendocrine tumors.

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are heterogeneous malignancies that arise from complex cellular interactions within the tissue microenvironment. Here, we sought to decipher tumor-derived signals from the surrounding microenvironment by applying digital spatial profiling (DSP) to hormone-secreting and non-functional GEP-NETs. By combining this approach with in vitro studies of human-derived organoids, we demonstrated the convergence of cell autonomous immune and pro-inflammatory proteins that suggests their role in neuroendocrine differentiation and tumorigenesis. DSP was used to evaluate the expression of 40 neural- and immune-related proteins in surgically resected duodenal and pancreatic NETs (n = 20) primarily consisting of gastrinomas (18/20). A total of 279 regions of interest were examined between tumors, adjacent normal and abnormal-appearing epithelium, and the surrounding stroma. The results were stratified by tissue type and multiple endocrine neoplasia I (MEN1) status, whereas protein expression was validated by immunohistochemistry (IHC). A tumor immune cell autonomous inflammatory signature was further evaluated by IHC and RNAscope, while functional pro-inflammatory signaling was confirmed using patient-derived duodenal organoids. Gastrin-secreting and non-functional pancreatic NETs showed a higher abundance of immune cell markers and immune infiltrate compared with duodenal gastrinomas. Compared with non-MEN1 tumors, MEN1 gastrinomas and preneoplastic lesions showed strong immune exclusion and upregulated expression of neuropathological proteins. Despite a paucity of immune cells, duodenal gastrinomas expressed the pro-inflammatory and pro-neural factor IL-17B. Treatment of human duodenal organoids with IL-17B activated NF-κB and STAT3 signaling and induced the expression of neuroendocrine markers. In conclusion, multiplexed spatial protein analysis identified tissue-specific neuro-immune signatures in GEP-NETs. Duodenal gastrinomas are characterized by an immunologically cold microenvironment that permits cellular reprogramming and neoplastic transformation of the preneoplastic epithelium. Moreover, duodenal gastrinomas cell autonomously express immune and pro-inflammatory factors, including tumor-derived IL-17B, that stimulate the neuroendocrine phenotype. © 2024 The Pathological Society of Great Britain and Ireland.

MENIN-mediated regulation of gastrin gene expression and its role in gastrinoma development.

The Multiple Endocrine Neoplasia I (MEN1) locus encodes the protein MENIN, which functions as a tumor suppressor protein in neuroendocrine tissues. Gastrinomas are neuroendocrine neoplasms that overproduce the hormone gastrin and can arise sporadically or as part of the MEN1 syndrome, in which mutations in the MEN1 gene lead to loss or inactivation of MENIN protein. Gastrin is a peptide hormone that is primarily synthesized in the gastric antrum and stimulates the secretion of histamine from enterochromaffin-like (ECL) cells and subsequently acid from parietal cells in the gastric corpus. In addition, gastrin exerts a mitogenic function primarily on ECL cells and progenitor cells in the gastric isthmus. Current studies seek to understand how MEN1 mutations generate a mutant MENIN protein that abrogates its tumor suppressor function. Mutations in the MEN1 gene are broadly distributed throughout its nine protein-coding exons, making it difficult to correlate protein structure with its function. Although disruption of the Men1 locus in mice causes functional neuroendocrine tumors in the pituitary and pancreas, gastrinomas do not develop in these transgenic animal models. Prior studies of human gastrinomas suggest that tissue-specific microenvironmental cues in the submucosal foregut may contribute to tumorigenesis by reprogramming of epithelial cells toward the neuroendocrine phenotype. Accordingly, recent studies suggest that neural crest-derived cells are also sensitive to reprogramming when MEN1 is deleted or mutated. Thus, the goal of this report is to review our current understanding of how MENIN modulates gastrin gene expression while highlighting its role in the prevention/suppression of neuroendocrine cell transformation.

The Expression of Autophagy-Associated Genes Represents a Valid Footprint for Aggressive Pancreatic Neuroendocrine Neoplasms.

Pancreatic neuroendocrine neoplasms (pNEN) are rare and heterogeneous tumors. Previous investigations have shown that autophagy can be a target for cancer therapy. This study aimed to determine the association between the expression of autophagy-associated gene transcripts and clinical parameters in pNEN. In total, 54 pNEN specimens were obtained from our human biobank. The patient characteristics were retrieved from the medical record. RT-qPCR was performed to assess the expression of the autophagic transcripts BECN1, MAP1LC3B, SQSTM1, UVRAG, TFEB, PRKAA1, and PRKAA2 in the pNEN specimens. A Mann-Whitney U test was used to detect differences in the expression of autophagic gene transcripts between different tumor characteristics. This study showed that G1 sporadic pNEN have a higher expression of autophagic genes compared to G2. Lymphatic and distant metastasis occurred significantly more often in pNEN with a decreased expression of the autophagic genes. Within sporadic pNEN, the insulinomas express higher levels of autophagic transcripts than gastrinomas and non-functional pNEN. MEN1-associated pNEN show a higher expression of autophagic genes than sporadic pNEN. In summary, a decreased expression of autophagic transcripts distinguishes metastatic from non-metastatic sporadic pNEN. The significance of autophagy as a molecular marker for prognosis and therapy decisions needs to be further investigated.

[Comparison of clinical characteristics between sporadic gastrinoma and multiple endocrine neoplasia type 1-related gastrinoma].

Objective: To compare clinical characteristics of sporadic gastrinoma and multiple endocrine neoplasia type 1 (MEN1)-related gastrinoma. Methods: A retrospective cohort study was conducted. Patients with clinical manifestations of Zollinger-Ellison syndrome, pathological diagnosis as neuroendocrine neoplasm (NEN) and complete clinical and follow-up data were enrolled. Patients with only high gastric acid secretion but without evidence of NEN, or with other concurrent non-NEN tumors were excluded. According to the above criteria, the clinicopathological data of 52 cases of gastrinoma diagnosed from April 2003 to December 2020 in the First Affiliated Hospital, Sun Yat-sen University, were collected. Patients who met the diagnostic criteria of gastrinoma and met one of the following conditions were diagnosed as MEN1-related gastrinoma: (1) the presence of pathogenic mutations in the MEN1 gene confirmed by genetic testing; (2) NENs involving two or more endocrine glands, namely, pituitary, parathyroid, thymic, pancreatic, and adrenal NENs; (3) NEN and at least one first-degree relatives diagnosed as MEN1. The remaining gastrinomas were defined as sporadic gastrinoma. Student's t test and chi-square test were used for statistical analysis. Clinicopathological characteristics, endoscopic findings, imaging characteristics, treatment, and prognosis of sporadic and MEN1-related gastrinoma were compared. Results: Among 52 patients with gastrinoma, 33 were sporadic gastrinoma and 19 were MEN1-related gastrinoma. The common symptoms of both sporadic and MEN1-related gastrinomas were diarrhea (24/33, 72.7%; 17/19, 89.5%) and abdominal pain (19/33, 57.6%; 9/19, 47.4%). Compared with sporadic gastrinoma, MEN1-related gastrinoma needed longer time for diagnosis [(7.4±4.9) years vs. (3.9±5.2) years, t=-2.355, P=0.022), were more likely multiple tumors [47.4% (9/19) vs. 15.2% (5/33), χ(2)=6.361, P=0.012], had smaller diameter [(1.7±1.0) cm vs. (3.1±1.8) cm, t=2.942, P=0.005), presented the lower tumor grade [G1: 83.3% (15/18) vs. 39.4% (13/33); G2: 11.1% (2/18) vs. 54.5% (18/33); G3: 5.6% (1/18) vs. 6.1% (2/33), Z=-2.766, P=0.006], were less likely to have serum gastrin which was 10 times higher than normal [11.8% (2/17) vs. 56.0% (14/33), χ(2)=8.396, P=0.004], had higher probability of complication with type 2 gastric neuroendocrine tumors (g-NET) [31.6% (6/19) vs. 3.0%(1/33), χ(2)=6.163, P=0.013], and had lower rate of liver metastasis [21.1% (4/19) vs. 51.5% (17/33), χ(2)=4.648, P=0.031). There was no obvious difference between sporadic gastrinomas and MEN1-related gastrinomas in endoscopic findings. Both types presented enlarged and swollen gastric mucosa under the stimulation of high gastric acid, and multiple ulcers in the stomach and duodenum could be seen. Gastrinoma with type 2 g-NET presented multiple polypoid raised lesions in the fundus and body of the stomach. (68)Ga-SSR-PET/CT scan had a 100% detection rate for both types while (18)F-FDG-PET/CT scan had a higher detection rate for sporadic gastrinoma compared with MEN1-related gastrinoma [57.9% (11/19) vs. 20.0% (3/15), χ(2)=4.970, P=0.026]. Among the patients with sporadic gastrinoma, 19 received surgical treatment, 1 underwent endoscopic submucosal dissection, 8 underwent transcatheter arterial embolization (TAE), and 5 underwent surgery combined with TAE. Among patients with MEN1-related gastrinoma, 13 received surgical treatment, and the other 6 received conservative treatment. The median follow-up of all the patients was 21.5 (1-129) months, and the 5-year survival rate was 88.4%. The 5-year survival rate of patients with sporadic and MEN1-related gastrinomas was 89.5% and 80.0% respectively (P=0.949). The 5-year survival rate of patients with and without liver metastasis was 76.2% vs. 100%, respectively (P=0.061). Conclusions: Compared with sporadic gastrinoma, MEN1-related gastrinoma has longer diagnosis delay, smaller tumor diameter, lower tumor grading, lower risk of liver metastasis, and is more likely to complicate with type 2 g-NET, while there is no difference in survival between the two tumor types.

A germline c.1546dupC MEN1 mutation in an MEN1 family: A case report.

RATIONALE: Multiple endocrine neoplasia type 1 (MEN1) is a rare tumor syndrome with an autosomal dominant inheritance, and genetic testing for MEN1 gene is important for both affected individuals and their relatives. We present a 2-person family affected by a germline c.1546dupC MEN1 mutation, and one of them had a full-spectrum of MEN-related endocrine tumors. PATIENT CONCERNS: A female patient aged 32 years presented with jejunal ulcer perforation due to gastrinoma. DIAGNOSES: We conducted genetic analysis and extensive biochemical/radiological evaluation for detecting other endocrine tumors. Multiple pancreatic neuroendocrine tumors (NETs), prolactinoma and primary hyperparathyroidism were diagnosed, and a frame-shift mutation, NM_130799.1:c.1546dupC (p.Arg516Profs∗15), was detected. One daughter of the proband, aged 12 years, had the same mutation for MEN1. INTERVENTION: She underwent pancreatic surgery for pancreatic NETs and total parathyroidectomy for primary hyperparathyroidism. OUTCOMES: After pancreatic surgery, long-term symptoms of epigastric soreness, acid belching, sweating, and palpitation in fasting were improved. Hypercalcemia was improved after parathyroidectomy and she was supplemented with oral calcium and vitamin D. Her daughter showed normal biochemical surveillance until 15 years of age. LESSONS: We report 2 people in a family affected by MEN1 with the heterozygous germline c.1546dupC mutation, a variant that should be surveilled for early development of full-blown MEN1-associated endocrine tumors.

Genomic profiling of multiple tissues in two patients with multiple endocrine neoplasia type 1.

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant tumor syndrome. This hereditary cancer is caused by germline variants in MEN1. Two patients with MEN1 were identified via whole exome sequencing and gene expression profile analysis, conducted for 5,063 patients with various types of cancers. We obtained multiple tumors from each patient; tumors derived from these two MEN1 patients had a loss of the normal MEN1 allele and frequently chromosomal copy number changes. Thus, we investigated whether structural variants were present in the MEN1 patient genomes. Whole-genome sequencing revealed no catastrophic rearrangements, and the tumor samples had very low somatic variants. The two patients had germline variants in MEN1 and some chromosomal copy number changes including on chromosome 11. The only pathogenic variant detected was the MEN1 germline variant, and chromosomal rearrangements led to tumorigenesis in somatic cells. Furthermore, the MEN1 tumor samples displayed a specific signature characterized by T:A>C:G transition. Studies of multiple tumors obtained from single patients are rare in hereditary cancer syndromes, and our results provide insights that the second hit of the tumor suppressor gene MEN1 may be caused by a gross genome rearrangement, not a small insertion and deletion, nor a change in epigenetic regulation.

New therapies for patients with multiple endocrine neoplasia type 1.

In 1953, for the first time, Paul Wermer described a family presenting endocrine gland neoplasms over several generations. The transmission was autosomal dominant and the penetrance was high. Forty years later in 1997, the multiple endocrine neoplasia type 1 (MEN1) gene was sequenced, thus enabling diagnosis and early optimal treatment. Patients carrying the MEN1 gene present endocrine but also non-endocrine tumors. Parathyroid, pancreatic and pituitary impairment are the three main types of endocrine involvement. The present article details therapeutic management of hyperparathyroidism, neuroendocrine pancreatic tumors and pituitary adenomas in patients carrying the MEN1 gene. Significant therapeutic progress has in fact been made in the last few years. As concerns the parathyroid glands, screening of family members and regular monitoring of affected subjects now raise the question of early management of parathyroid lesions and optimal timing of parathyroid surgery. As concerns the duodenum-pancreas, proton-pump inhibitors are able to control gastrin-secreting syndrome, reducing mortality in MEN1 patients. Mortality in MEN1 patients is no longer mainly secondary to uncontrolled hormonal secretion but to metastatic (mainly pancreatic) disease progression. Tumor risk requires regular monitoring of morphological assessment, leading to iterative pancreatic surgery in a large number of patients. Finally, pituitary adenomas in MEN1 patients are traditionally described as aggressive, invasive and resistant to medical treatment. However, regular pituitary screening showed them to be in fact infra-centimetric and non-secreting in the majority of patients. Consequently, it is necessary to regularly monitor MEN1 patients, with regular clinical, biological and morphological work-up. Several studies showed that this regular monitoring impairs quality of life. Building a relationship of trust between patients and care provider is therefore essential. It enables the patient to be referred for psychological or psychiatric care in difficult times, providing long-term support and preventing any breakdown in continuity of care.

A Parathyroid-Gut Axis: Hypercalcemia and the Pathogenesis of Gastrinoma in Multiple Endocrine Neoplasia 1.

Patients with multiple endocrine neoplasia 1 (MEN1) syndrome have a germline mutation in the MEN1 gene. Loss of the wild-type allele can initiate endocrine tumorigenesis. Microscopic and macroscopic pituitary, parathyroid, and pancreatic tumors (referred to as the 3 P's) show loss of the wild-type MEN1 allele up to 100%. In contrast, the duodenal gastrinoma pathogenesis in MEN1 syndrome follows a hyperplasia-to-neoplasia sequence. Gastrinomas have loss of heterozygosity of the MEN1 locus in <50%, and invariably coincide with linear, diffuse, or micronodular gastrin-cell hyperplasia. The factor initiating the gastrin-cell hyperplasia-to-neoplasia sequence is unknown. In this perspective, we argue that hypercalcemia may promote the gastrin-cell hyperplasia-to-neoplasia sequence through the calcium sensing receptor. Hypercalcemia is present in almost all patients with MEN1 syndrome due to parathyroid adenomas. We propose a parathyroid-gut axis, which could well explain why patients with MEN1 syndrome are regularly cured of duodenal gastrinoma after parathyroid surgery, and might cause MEN1 syndrome phenocopies in MEN1-mutation negative individuals with parathyroid adenomas. This perspective on the pathogenesis of the gastrin-cell hyperplasia and neoplasia sequence sheds new light on tumorigenic mechanisms in neuroendocrine tumors and might open up novel areas of gastrinoma research. It may also shift focus in the treatment of MEN1 syndrome-related gastrinoma to biochemical prevention.

Comparison of clinical characteristics between sporadic gastrinoma and multiple endocrine neoplasia type 1-related gastrinoma / 中华胃肠外科杂志

Objective: To compare clinical characteristics of sporadic gastrinoma and multiple endocrine neoplasia type 1 (MEN1)-related gastrinoma. Methods: A retrospective cohort study was conducted. Patients with clinical manifestations of Zollinger-Ellison syndrome, pathological diagnosis as neuroendocrine neoplasm (NEN) and complete clinical and follow-up data were enrolled. Patients with only high gastric acid secretion but without evidence of NEN, or with other concurrent non-NEN tumors were excluded. According to the above criteria, the clinicopathological data of 52 cases of gastrinoma diagnosed from April 2003 to December 2020 in the First Affiliated Hospital, Sun Yat-sen University, were collected. Patients who met the diagnostic criteria of gastrinoma and met one of the following conditions were diagnosed as MEN1-related gastrinoma: (1) the presence of pathogenic mutations in the MEN1 gene confirmed by genetic testing; (2) NENs involving two or more endocrine glands, namely, pituitary, parathyroid, thymic, pancreatic, and adrenal NENs; (3) NEN and at least one first-degree relatives diagnosed as MEN1. The remaining gastrinomas were defined as sporadic gastrinoma. Student's t test and chi-square test were used for statistical analysis. Clinicopathological characteristics, endoscopic findings, imaging characteristics, treatment, and prognosis of sporadic and MEN1-related gastrinoma were compared. Results: Among 52 patients with gastrinoma, 33 were sporadic gastrinoma and 19 were MEN1-related gastrinoma. The common symptoms of both sporadic and MEN1-related gastrinomas were diarrhea (24/33, 72.7%; 17/19, 89.5%) and abdominal pain (19/33, 57.6%; 9/19, 47.4%). Compared with sporadic gastrinoma, MEN1-related gastrinoma needed longer time for diagnosis [(7.4±4.9) years vs. (3.9±5.2) years, t=-2.355, P=0.022), were more likely multiple tumors [47.4% (9/19) vs. 15.2% (5/33), χ(2)=6.361, P=0.012], had smaller diameter [(1.7±1.0) cm vs. (3.1±1.8) cm, t=2.942, P=0.005), presented the lower tumor grade [G1: 83.3% (15/18) vs. 39.4% (13/33); G2: 11.1% (2/18) vs. 54.5% (18/33); G3: 5.6% (1/18) vs. 6.1% (2/33), Z=-2.766, P=0.006], were less likely to have serum gastrin which was 10 times higher than normal [11.8% (2/17) vs. 56.0% (14/33), χ(2)=8.396, P=0.004], had higher probability of complication with type 2 gastric neuroendocrine tumors (g-NET) [31.6% (6/19) vs. 3.0%(1/33), χ(2)=6.163, P=0.013], and had lower rate of liver metastasis [21.1% (4/19) vs. 51.5% (17/33), χ(2)=4.648, P=0.031). There was no obvious difference between sporadic gastrinomas and MEN1-related gastrinomas in endoscopic findings. Both types presented enlarged and swollen gastric mucosa under the stimulation of high gastric acid, and multiple ulcers in the stomach and duodenum could be seen. Gastrinoma with type 2 g-NET presented multiple polypoid raised lesions in the fundus and body of the stomach. (68)Ga-SSR-PET/CT scan had a 100% detection rate for both types while (18)F-FDG-PET/CT scan had a higher detection rate for sporadic gastrinoma compared with MEN1-related gastrinoma [57.9% (11/19) vs. 20.0% (3/15), χ(2)=4.970, P=0.026]. Among the patients with sporadic gastrinoma, 19 received surgical treatment, 1 underwent endoscopic submucosal dissection, 8 underwent transcatheter arterial embolization (TAE), and 5 underwent surgery combined with TAE. Among patients with MEN1-related gastrinoma, 13 received surgical treatment, and the other 6 received conservative treatment. The median follow-up of all the patients was 21.5 (1-129) months, and the 5-year survival rate was 88.4%. The 5-year survival rate of patients with sporadic and MEN1-related gastrinomas was 89.5% and 80.0% respectively (P=0.949). The 5-year survival rate of patients with and without liver metastasis was 76.2% vs. 100%, respectively (P=0.061). Conclusions: Compared with sporadic gastrinoma, MEN1-related gastrinoma has longer diagnosis delay, smaller tumor diameter, lower tumor grading, lower risk of liver metastasis, and is more likely to complicate with type 2 g-NET, while there is no difference in survival between the two tumor types.

Prognostic relevance of proliferation-related miRNAs in pancreatic neuroendocrine neoplasms

Objective: Pancreatic neuroendocrine neoplasms (PanNENs) are rare tumors arising from the endocrine pancreas; however, their prognosis differs significantly upon their proliferative state, which is characterized by histopathological grading. MiRNAs are small, noncoding RNAs posttranscriptionally regulating gene expression. Our aim was to identify miRNAs with altered expression upon proliferation which can be used as prognostic biomarkers in PanNENs. Methods: MiRNA expression profiles of 40 PanNENs were downloaded from Gene Expression Omnibus and were reanalyzed upon tumor grades (discovery cohort). Results of the reanalysis were confirmed by qRT-PCR analysis of five miRNAs on an independent validation cohort of 63 primary PanNEN samples. Cox proportional hazards survival regression models were fit for both univariate and multivariate analysis to determine the miRNAs' effect on progression-free and overall survival. Results: Nineteen miRNAs displayed differential expression between tumor grades. The altered expression of three out of five chosen miRNAs was successfully validated; hsa-miR-21, hsa-miR-10a and hsa-miR-106b were upregulated in more proliferative PanNENs compared to Grade 1 tumors. In univariate analysis, higher expression of tissue hsa-miR-21, hsa-miR-10a and hsa-miR-106b of primary PanNENs predicted worse progression-free and overall survival; however, multivariate analysis only confirmed the expression of hsa-miR-21 as an independent prognostic factor. Conclusions: The expression of hsa-miR-106b, hsa-miR-10a and especially hsa-miR-21 has prognostic relevance regarding progression-free and overall survival in patients with PanNENs.

Gastrin Induces Nuclear Export and Proteasome Degradation of Menin in Enteric Glial Cells.

BACKGROUND & AIMS: The multiple endocrine neoplasia, type 1 (MEN1) locus encodes the nuclear protein and tumor suppressor menin. MEN1 mutations frequently cause neuroendocrine tumors such as gastrinomas, characterized by their predominant duodenal location and local metastasis at time of diagnosis. Diffuse gastrin cell hyperplasia precedes the appearance of MEN1 gastrinomas, which develop within submucosal Brunner's glands. We investigated how menin regulates expression of the gastrin gene and induces generation of submucosal gastrin-expressing cell hyperplasia. METHODS: Primary enteric glial cultures were generated from the VillinCre:Men1FL/FL:Sst-/- mice or C57BL/6 mice (controls), with or without inhibition of gastric acid by omeprazole. Primary enteric glial cells from C57BL/6 mice were incubated with gastrin and separated into nuclear and cytoplasmic fractions. Cells were incubated with forskolin and H89 to activate or inhibit protein kinase A (a family of enzymes whose activity depends on cellular levels of cyclic AMP). Gastrin was measured in blood, tissue, and cell cultures using an ELISA. Immunoprecipitation with menin or ubiquitin was used to demonstrate post-translational modification of menin. Primary glial cells were incubated with leptomycin b and MG132 to block nuclear export and proteasome activity, respectively. We obtained human duodenal, lymph node, and pancreatic gastrinoma samples, collected from patients who underwent surgery from 1996 through 2007 in the United States or the United Kingdom. RESULTS: Enteric glial cells that stained positive for glial fibrillary acidic protein (GFAP+) expressed gastrin de novo through a mechanism that required PKA. Gastrin-induced nuclear export of menin via cholecystokinin B receptor (CCKBR)-mediated activation of PKA. Once exported from the nucleus, menin was ubiquitinated and degraded by the proteasome. GFAP and other markers of enteric glial cells (eg, p75 and S100B), colocalized with gastrin in human duodenal gastrinomas. CONCLUSIONS: MEN1-associated gastrinomas, which develop in the submucosa, might arise from enteric glial cells through hormone-dependent PKA signaling. This pathway disrupts nuclear menin function, leading to hypergastrinemia and associated sequelae.

Natural History of MEN1 GEP-NET: Single-Center Experience After a Long Follow-Up.

BACKGROUND: The multiple endocrine neoplasia type 1 syndrome (MEN1) natural history is poorly evaluated, and few single-institution experiences about hereditary gastroenteropancreatic neuroendocrine tumors (GEP-NET) are reported. Our purpose is to analyze the role of GEP-NET in MEN1-related death, as well as the behavior of these lesions during follow-up. METHODS: The study population consists of 77 patients diagnosed with MEN1 GEP-NET, regularly followed up since 1990. Extensive clinical data were prospectively recorded. Statistical analysis was performed both on the whole population of 77 patients and on two subgroups including patients who, during the long lasting study period, underwent GEP-NET surgery (50 pts) and who did not (27 pts), respectively. RESULTS: Twenty-five males (32.5%) and 52 females (67.5%) were enrolled. Sixty-four patients had MEN1 family history (83.1%), and genetic mutation was detected in 67 cases (87%). The mean age at GEP-NET diagnosis was 41.4 years (SD = 13.6); 16 patients (20.8%) had GEP-NET diagnosed before age 30 and 12 cases (15.6%) before 1996. The mean interval time between MEN1 diagnosis and GEP-NET detection was 5.7 years (range -11/37; SD = 8.1 years). Overall, the mean follow-up time from MEN1 diagnosis was 15.8 years (SD = 9.7 years) and from GEP-NET diagnosis was 9.6 years (SD = 6.9 years). Gastrinoma was the most frequent functioning GEP-NET and pancreatoduodenectomy the most adopted surgery. GEP-NET progression affected 12 patients within the non-surgical group, while 18 subjects developed progression after surgery. CONCLUSIONS: Our single-center data provide information on epidemiologic, clinical and pathological features of GEP-NET in MEN1 making possible to clarify their natural history.

Chromogranin A in gastrinomas: Promises and pitfalls.

Patients with neuroendocrine tumors are found with increasing frequency. Accordingly, knowledge about relevant tumor markers and assays for diagnosis and control has become essential. Neuroendocrine tumors release one or more granin proteins. Of these, chromogranin A (CgA) has so far become the most widely used general marker. The CgA protein is, however, extensively cleaved and otherwise modified during the biosynthetic processing. In addition, the CgA-processing in individual tumors varies considerably. But only few CgA-assays have taken the processing into account and characterized the assays with respect to precise epitope-specificity. Consequently, we do not know which fragments most CgA-assays measure. It is therefore at present difficult to compare CgA-measurements from tumor patients. Some tumors, however, release - in addition to granins - also a specific hormone that causes a clinical syndrome. This review uses gastrinomas (gastrin-producing tumors) as a starting point for discussion of CgA versus peptide hormone as tumor marker. Data available so far indicate that well-defined assays for gastrin have significantly higher diagnostic sensitivity than CgA measurements in gastrinomas. But the review suggests that CgA-quantitation using processing-independent analysis (PIA) may provide an equally high diagnostic sensitivity and in addition offer a simple possibility for estimation of the tumor-burden.

Deletions of RDINK4/ARF enhancer in gastrinomas and nonfunctioning pancreatic neuroendocrine tumors.

OBJECTIVE: The presence of an enhancer element, RD (RD), in the prominent INK4-ARF locus provides a novel en bloc mechanism to simultaneously regulate the transcription of p15, p14ARF, and p16 genes. However, knowledge about RD alterations and its potential contributions to cancer progression remains limited. In this study, we aimed to evaluate the incidence of RD alterations in pancreatic tumors. METHODS: DNAs from 14 gastrinomas and 6 nonfunctioning pancreatic neuroendocrine tumors were subjected to quantitative real-time polymerase chain reaction-based assays to determine deletions in p15, p14ARF, and p16 (both exons 1 and 2). RESULTS: RD was frequently deleted in gastrinomas and nonfunctioning pancreatic neuroendocrine tumors with an incidence of 30% (6/20 samples). In comparison, the incidences of deletions of p15 (exon 1), p14ARF (exon 1ß), and p16 (exon 1α) are 10% (2/20 samples), 10% (2/20 samples), and 45% (9/20 samples), respectively. Whereas some RD deletion events arose from deletions of the entire INK4-ARF locus, RD deletions in some specimens seemed to be independent of genetic alterations in any of the p15, p14ARF, and p16 genes. CONCLUSIONS: Our results strongly support that the deletion of RD may represent a novel mechanism to simultaneously downregulate p15, p14ARF, and p16, thus contributing to the development of human pancreatic cancers.

A rare case of malignant epithelioid angiomyolipoma in multiple locations: multifocal disease or metastases?

BACKGROUND: Perivascular epithelioid cell tumors (PEComas), make up a family of extremely rare mesenchymal neoplasms, with characteristic morphological, immunohistochemical and molecular findings. Malignant PEComas and gastrointestinal epithelioid angiomyolipoma (E-AML) are especially rare. To the best of our knowledge E-AML have not been found in the breast. The difficulty in determining what constitutes optimal therapy for PEComas, owing to the sparse literature available, led us to report this rare case. METHODS: We report a case of a 44-year-old woman, with a family history of multiple endocrine neoplasia syndrome (MEN) (gastrinoma, medullary thyroid cancer and parathyroid hyperplasia), affected by PEComa located in the kidney, stomach, ileum, liver and breast. RESULTS: The renal, gastric, ileal and mammarian tumors were completely resected, with no evidence of local disease. Liver lesions were biopsied. The morphological and immunohistochemical findings confirm the diagnosis of PEComa. CONCLUSION: On this basis it is difficult to determine if some E-AML are multifocal tumors or metastatic disease.

Surgical treatment of pancreatic endocrine tumors in multiple endocrine neoplasia type 1.

Surgical approaches to pancreatic endocrine tumors associated with multiple endocrine neoplasia type 1 may differ greatly from those applied to sporadic pancreatic endocrine tumors. Presurgical diagnosis of multiple endocrine neoplasia type 1 is therefore crucial to plan a proper intervention. Of note, hyperparathyroidism/multiple endocrine neoplasia type 1 should be surgically treated before pancreatic endocrine tumors/multiple endocrine neoplasia type 1 resection, apart from insulinoma. Non-functioning pancreatic endocrine tumors/multiple endocrine neoplasia type 1 >1 cm have a high risk of malignancy and should be treated by a pancreatic resection associated with lymphadenectomy. The vast majority of patients with gastrinoma/multiple endocrine neoplasia type 1 present with tumor lesions at the duodenum, so the surgery of choice is subtotal or total pancreatoduodenectomy followed by regional lymphadenectomy. The usual surgical treatment for insulinoma/multiple endocrine neoplasia type 1 is distal pancreatectomy up to the mesenteric vein with or without spleen preservation, associated with enucleation of tumor lesions in the pancreatic head. Surgical procedures for glucagonomas, somatostatinomas, and vipomas/ multiple endocrine neoplasia type 1 are similar to those applied to sporadic pancreatic endocrine tumors. Some of these surgical strategies for pancreatic endocrine tumors/multiple endocrine neoplasia type 1 still remain controversial as to their proper extension and timing. Furthermore, surgical resection of single hepatic metastasis secondary to pancreatic endocrine tumors/multiple endocrine neoplasia type 1 may be curative and even in multiple liver metastases surgical resection is possible. Hepatic trans-arterial chemo-embolization is usually associated with surgical resection. Liver transplantation may be needed for select cases. Finally, pre-surgical clinical and genetic diagnosis of multiple endocrine neoplasia type 1 syndrome and localization of multiple endocrine neoplasia type 1 related tumors are crucial for determining the best surgical strategies in each individual case with pancreatic endocrine tumors.

Surgical treatment of pancreatic endocrine tumors in multiple endocrine neoplasia type 1

Surgical approaches to pancreatic endocrine tumors associated with multiple endocrine neoplasia type 1 may differ greatly from those applied to sporadic pancreatic endocrine tumors. Presurgical diagnosis of multiple endocrine neoplasia type 1 is therefore crucial to plan a proper intervention. Of note, hyperparathyroidism/multiple endocrine neoplasia type 1 should be surgically treated before pancreatic endocrine tumors/multiple endocrine neoplasia type 1 resection, apart from insulinoma. Non-functioning pancreatic endocrine tumors/multiple endocrine neoplasia type 1 >1 cm have a high risk of malignancy and should be treated by a pancreatic resection associated with lymphadenectomy. The vast majority of patients with gastrinoma/multiple endocrine neoplasia type 1 present with tumor lesions at the duodenum, so the surgery of choice is subtotal or total pancreatoduodenectomy followed by regional lymphadenectomy. The usual surgical treatment for insulinoma/multiple endocrine neoplasia type 1 is distal pancreatectomy up to the mesenteric vein with or without spleen preservation, associated with enucleation of tumor lesions in the pancreatic head. Surgical procedures for glucagonomas, somatostatinomas, and vipomas/ multiple endocrine neoplasia type 1 are similar to those applied to sporadic pancreatic endocrine tumors. Some of these surgical strategies for pancreatic endocrine tumors/multiple endocrine neoplasia type 1 still remain controversial as to their proper extension and timing. Furthermore, surgical resection of single hepatic metastasis secondary to pancreatic endocrine tumors/multiple endocrine neoplasia type 1 may be curative and even in multiple liver metastases surgical resection is possible. Hepatic trans-arterial chemo-embolization is usually associated with surgical resection. Liver transplantation may be needed for select cases. Finally, pre-surgical clinical and genetic diagnosis of multiple endocrine neoplasia type 1 syndrome and localization of multiple endocrine neoplasia type 1related tumors are crucial for determining the best surgical strategies in each individual case with pancreatic endocrine tumors.

[About a case of multiple endocrine neoplasia type 1. Review of some clinical manifestations and treatment controversies]. / A propósito de un caso de neoplasia endocrina múltiple tipo 1. Revisión de algunas manifestaciones clínicas y controversias en el tratamiento.

The rare hereditary syndrome, multiple endocrine neoplasia type1 (MEN-1), is known to predispose affected individuals to endocrine neoplasms in a variety of tissues such as the parathyroid glands, the pituitary gland and the gastrointestinal tract. We describe the case of a man with traditionally-described manifestations (hyperparathyroidism and gastrinoma) and with other tumoral lesions arising from endocrine cells (insulinoma, gastric carcinoid, adrenal adenoma and pancreatic non-functioning neuroendocrine tumors) and non-endocrine cells (lipoma and collagenoma). Frequent recurrences in susceptible tissues that are not totally removed (as occurs in hyperparathyroidism and duodenal gastrinoma) and their unknown clinical significance have aroused current controversies in the therapeutic management of these entities, which is briefly reviewed.

A propósito de un caso de neoplasia endocrina múltiple tipo 1. Revisión de algunas manifestaciones clínicas y controversias en el tratamiento / About a case of multiple endocrine neoplasia type1. Review of some clinical manifestations and treatment controversies

La neoplasia endocrina múltiple de tipo 1 (MEN1) es un síndrome hereditario raro conocido por la predisposición a la aparición de neoplasias endocrinas en distintos tejidos como paratiroides, hipófisis y tracto gastrointestinal. Se presenta el caso de un varón en el que además de manifestaciones tradicionalmente descritas (hipeparatiroidismo y gastrinoma) se objetivan otras lesiones tumorales procedentes de células de estirpe endocrinológica (insulinoma, carcinoide gástrico, adenoma suprarrenal, tumores neuroendocrino no funcionantes del páncreas) y no endocrinológica (lipoma y colagenoma). La frecuente recurrencia de las lesiones sobre los tejidos susceptibles no resecados en su totalidad (como en el caso del hiperparatiroidismo y del gastrinoma duodenal) y las dudas sobre su significado clínico en el MEN1 suscitan cierta controversia en la actualidad sobre las recomendaciones en el manejo terapéutico de dichas lesiones que se revisa brevemente (AU)

The rare hereditary syndrome, multiple endocrine neoplasia type1 (MEN-1), is known to predispose affected individuals to endocrine neoplasms in a variety of tissues such as the parathyroid glands, the pituitary gland and the gastrointestinal tract. We describe the case of a man with traditionally-described manifestations (hyperparathyroidism and gastrinoma)and with other tumoral lesions arising from endocrine cells (insulinoma, gastric carcinoid,adrenal adenoma and pancreatic non-functioning neuroendocrine tumors) and non-endocrinecells (lipoma and collagenoma). Frequent recurrences in susceptible tissues that are not totally removed (as occurs in hyperparathyroidism and duodenal gastrinoma) and their unknown clinical significance have aroused current controversies in the therapeutic management of these entities, which is briefly reviewed (AU)