Clinical features and prognosis of malignant small bowel tumors: Experience from a university hospital in Chile / Características clínicas y pronóstico de los tumores malignos de intestino delgado: experiencia en un hospital universitario de Chile

Background Small bowel tumors (SBT) are infrequent and represent a small proportion of digestive neoplasms. There is scarce information about SBT in Latin America.AimTo describe the epidemiology, clinical characteristics, diagnostic methods, and survival of malignant SBTs.MethodsRetrospective observational study of adult patients with histopathological diagnosis of SBT between 2007 and 2021 in a university hospital in Chile.ResultsA total of 104 patients [51.9% men; mean age 57 years] with SBT. Histological type: neuroendocrine tumor (NET) (43.7%, n=38), gastrointestinal stromal tumors (GIST) (21.8%, n=19), lymphoma (17.2%, n=15) and adenocarcinoma (AC) (11.5%, n=10). GIST was more frequent in duodenum (50%; n=12) and NET in the ileum (65.8%; n=25). Metastasis was observed in 17 cases, most commonly from colon and melanoma. Nausea and vomiting were significantly more often observed in AC (p=0.035), as well as gastrointestinal bleeding in GIST (p=0.007). The most common diagnostic tools were CT and CT enteroclysis with an elevated diagnostic yield (86% and 94% respectively). The 5-year survival of GIST, NET, lymphoma and AC were 94.7% (95%CI: 68.1–99.2), 82.2% (95%CI: 57.6–93.3), 40.0% (95%CI: 16.5–82.8) and 25.9% (95%CI: 4.5–55.7%), respectively. NET (HR 6.1; 95%CI: 2.1–17.2) and GIST (HR 24.4; 95%CI: 3.0–19.8) were independently associated with higher survival compared to AC, adjusted for age and sex.ConclusionsMalignant SBT are rare conditions and NETs are the most common histological subtype. Clinical presentation at diagnosis, location or complications may suggest a more probable diagnosis. GIST and NET are associated with better survival compared to other malignant subtypes. (AU)

Introducción Los tumores del intestino delgado (TID) son infrecuentes y la información sobre ellos es escasa en Latinoamérica.ObjetivoDescribir la epidemiología, características clínicas, métodos diagnósticos y supervivencia de los TID malignos.MétodosEstudio observacional retrospectivo de pacientes adultos con diagnóstico histopatológico de TID entre 2007-2021 en un hospital universitario de Chile.ResultadosSe observaron 104 pacientes (51,9% hombres; edad media 57 años) con TID. El tipo histológico fue tumor neuroendocrino (TNE) (43,7%, n=38), tumor estromal gastrointestinal (GIST) (21,8%, n=19), linfoma (17,2%, n=15) y adenocarcinoma (AC) (11,5%, n=10). Los GIST fueron más frecuentes en el duodeno (50%; n=12) y los TNE en el íleon (65,8%; n=25). Hubo 17 casos de metástasis, más comúnmente de colon y melanoma. Las náuseas y los vómitos se observaron con mayor frecuencia en AC (p=0,035), así como el sangrado gastrointestinal en GIST (p=0,007). Las herramientas de valoración más comunes fueron TC y enteroclisis por TC con un rendimiento diagnóstico alto (86% y 94%, respectivamente). La supervivencia a cinco años de los GIST, TNE, linfoma y AC fue 94,7% (intervalo de confianza [IC] 95%: 68,1-99,2), 82,2% (IC 95%: 57,6-93,3), 40,0% (IC 95%: 16,5-82,8) y 25,9% (IC 95%: 4,5-55,7), respectivamente. Los TNE (hazard ratio [HR] 6,1; IC 95%: 2,1-17,2) y GIST (HR 24,4; IC 95%: 3,0-19,8) se asociaron de forma independiente con una mayor supervivencia en comparación con AC, ajustado por edad y sexo.ConclusionesLos TID malignos son enfermedades poco frecuentes y los TNE son el subtipo histológico más común. La presentación clínica en el momento del diagnóstico, localización o complicaciones pueden sugerir un dictamen más probable. Los GIST y TNE se asocian a una mejor supervivencia en comparación con otros subtipos malignos. (AU)

Toll-like receptors 1-9 in small bowel neuroendocrine tumors-Clinical significance and prognosis.

Toll-like receptors (TLRs) are pattern recognition receptors of the innate immunity. TLRs are known to mediate both antitumor effects and tumorigenesis. TLRs are abundant in many cancers, but their expression in small bowel neuroendocrine tumors (SB-NETs) is unknown. We aimed to characterize the expression of TLRs 1-9 in SB-NETs and lymph node metastases and evaluate their prognostic relevance. The present study included 125 patients with SB-NETs, of whom 95 had lymph node metastases, from two Finnish hospitals. Tissue samples were stained immunohistochemically for TLR expression, assessed based on cytoplasmic and nucleic staining intensity and percentage of positively stained cells. Statistical methods for survival analysis included Kaplan-Meier method and Cox regression adjusted for confounding factors. Disease-specific survival (DSS) was the primary outcome. TLRs 1-2 and 4-9 were expressed in SB-NETs and lymph node metastases. TLR3 showed no positive staining. In primary SB-NETs, TLRs 1-9 were not associated with survival. For lymph node metastases, high cytoplasmic TLR7 intensity associated with worse DSS compared to low cytoplasmic intensity (26.4% vs. 84.9%, p = 0.028). Adjusted mortality hazard (HR) was 3.90 (95% CI 1.07-14.3). The expression of TLRs 1-6 and 8-9 in lymph node metastases were not associated with survival. SB-NETs and their lymph node metastases express cytoplasmic TLR 1-2 and 4-9 and nucleic TLR5. High TLR7 expression in SB-NET lymph node metastases was associated with worse prognosis. The current research has future perspective, as it can help create base for clinical drug trials to target specific TLRs with agonists or antagonists to treat neuroendocrine tumors.

Iron Supplementation Increases Tumor Burden and Alters Protein Expression in a Mouse Model of Human Intestinal Cancer.

Iron supplements are widely consumed. However, excess iron may accelerate intestinal tumorigenesis. To determine the effect of excess iron on intestinal tumor burden and protein expression changes between tumor and normal tissues, ApcMin/+ mice were fed control (adequate) and excess iron (45 and 450 mg iron/kg diet, respectively; n = 9/group) for 10 wk. Tumor burden was measured, and two-dimensional fluorescence difference gel electrophoresis was used to identify differentially expressed proteins in tumor and normal intestinal tissues. There was a significant increase (78.3%; p ≤ 0.05) in intestinal tumor burden (mm2/cm) with excess iron at wk 10. Of 980 analyzed protein spots, 69 differentially expressed (p ≤ 0.05) protein isoforms were identified, representing 55 genes. Of the isoforms, 56 differed (p ≤ 0.05) between tumor vs. normal tissues from the adequate iron group and 23 differed (p ≤ 0.05) between tumors from the adequate vs. excess iron. Differentially expressed proteins include those involved in cell integrity and adaptive response to reactive oxygen species (including, by gene ID: ANPEP, DPP7, ITGB1, PSMA1 HSPA5). Biochemical pathway analysis found that iron supplementation modulated four highly significant (p ≤ 0.05) functional networks. These findings enhance our understanding of interplay between dietary iron and intestinal tumorigenesis and may help develop more specific dietary guidelines regarding trace element intake.

Multiple sarcomatoid carcinomas in the small intestine with perforation: A case report and literature review.

RATIONALE: Sarcomatoid carcinoma of the small intestine is an exceedingly rare and aggressive malignancy, often diagnosed at advanced stages with a poor prognosis. This study documents a detailed case of sarcomatoid carcinoma of the small intestine, highlighting the diagnostic challenges and treatment approaches, underscored by a comprehensive review of related literature. Given the rarity of this condition, our report aims to enrich the existing diagnostic and treatment frameworks for this malignancy, emphasizing the necessity for early detection and intervention strategies. By presenting this case in conjunction with a literature review, we seek to shed light on the elusive nature of sarcomatoid carcinoma in the small intestine and propose avenues for improving patient outcomes. PATIENT CONCERNS: Case presentation A 61-year-old male patient initially presented with recurrent abdominal pain and gastrointestinal symptoms. Initial abdominal computed tomography (CT) scans and gastrointestinal endoscopy revealed only inflammatory and hyperplastic changes in the duodenum and jejunum, with a diagnosis of intestinal obstruction. Two years later, due to gastrointestinal perforation, the patient was hospitalized again. DIAGNOSES: CT scans and other examinations revealed small intestinal lesions. Four small intestinal lesions were surgically removed, and pathology and immunohistochemistry confirmed sarcomatoid carcinoma of the small intestine. A short time later, enhanced CT scans revealed metastatic lesions in the hepatic portal and adrenal glands. INTERVENTIONS: After surgery, the gastrointestinal function gradually recovered, and the patient was discharged from the hospital on a semiliquid diet. No further treatment such as radiotherapy or chemotherapy was administered postoperatively. OUTCOMES: Five months after the surgery, the patient died due to brain metastasis. LESSONS: The study outcomes reveal the aggressive nature of sarcomatoid carcinoma of the small intestine, characterized by rapid progression and poor prognosis despite surgical interventions. The patient condition rapidly deteriorated, leading to metastasis and death within 5 months postsurgery. These findings underscore the critical need for early detection and possibly innovative treatment approaches to improve survival rates. This case also highlights the potential for gastrointestinal sarcomatoid carcinoma to metastasize to distant organs, including the brain, suggesting a propensity for hematogenous spread.

[A Case of Five Years Recurrence-Free Survival after Successful Multidisciplinary Treatment for Simultaneous Brain Metastasis and Heterochronic Small Intestinal Metastasis from Lung Cancer].

The patient was a 54-year-old male at the time of initial examination. He was aware of numbness and weakness in the left hemisphere of his body and came to see the hospital. He was diagnosed with brain metastasis of lung cancer and started treatment(cT2N0M1[Brain]). He underwent gamma knife for the head lesion and nivolumab for the lung lesion. The patient's lesions shrank with the success of the medical treatment, but recurred with small intestinal metastasis. He underwent a partial resection of the small intestine and was treated again with nivolumab, which resulted in a complete response. He is currently alive without recurrence. We have experienced a very rare case of recurrence-free survival after treatment for brain metastasis and small intestinal metastasis of lung cancer.

Combined effects of radiation and simulated microgravity on intestinal tumorigenesis in C3B6F1 ApcMin/+ mice.

Explorations of the Moon and Mars are planned as future manned space missions, during which humans will be exposed to both radiation and microgravity. We do not, however, know the health effects for such combined exposures. In a ground-based experiment, we evaluated the combined effects of radiation and simulated microgravity on tumorigenesis by performing X-irradiation and tail suspension in C3B6F1 ApcMin/+ mice, a well-established model for intestinal tumorigenesis. Mice were irradiated at 2 weeks of age and underwent tail suspension for 3 or 11 weeks using a special device that avoids damage to the tail. The tail suspension treatment significantly reduced the thymus weight after 3 weeks but not 11 weeks, suggesting a transient stress response. The combination of irradiation and tail suspension significantly increased the number of small intestinal tumors less than 2 mm in diameter as compared with either treatment alone. The combined treatment also increased the fraction of malignant tumors among all small intestinal tumors as compared with the radiation-only treatment. Thus, the C3B6F1 ApcMin/+ mouse is a useful model for assessing cancer risk in a simulated space environment, in which simulated microgravity accelerates tumor progression when combined with radiation exposure.

Clinical features of intussusception in children secondary to small bowel tumours: a retrospective study of 31 cases.

BACKGROUND: Summarizing the clinical features of children with intussusception secondary to small bowel tumours and enhancing awareness of the disease. METHODS: Retrospective summary of children with intussusception admitted to our emergency department from January 2016 to January 2022, who underwent surgery and were diagnosed with small bowel tumours. Summarize the types of tumours, clinical presentation, treatment, and prognosis. RESULTS: Thirty-one patients were included in our study, 24 males and 7 females, with an age of onset ranging from 1 m to 11y 5 m. Post-operative pathology revealed 4 types of small intestinal tumour, 17 lymphomas, 10 adenomas, 4 inflammatory myofibroblastomas and 1 lipoma. The majority of tumours in the small bowel occur in the ileum (83.9%, 26/31). Abdominal pain, vomiting and bloody stools were the most common clinical signs. Operative findings indicated that the small bowel (54.8%, 17/31) and ileocolic gut were the main sites of intussusception. Two types of procedure were applied: segmental bowel resection (28 cases) and wedge resection of mass in bowel wall (3 cases). All patients recovered well postoperatively, with no surgical complications observed. However, the primary diseases leading to intussusception showed slight differences in long-term prognosis due to variations in tumor types. CONCLUSIONS: Lymphoma is the most common cause of intussusception in pediatric patients with small bowel tumours, followed by adenoma. Small bowel tumours in children tend to occur in the ileum. Therefore, the treatment of SBT patients not only requires surgeons to address symptoms through surgery and obtain tissue samples but also relies heavily on the expertise of pathologists for accurate diagnosis. This has a significant impact on the overall prognosis of these patients.

Prevalence of metastases outside the liver and abdominal lymph nodes on 68Ga-DOTATOC-PET/CT in patients with small intestinal and pancreatic neuroendocrine tumours.

Metastases outside the liver and abdominal/retroperitoneal lymph nodes are nowadays detected frequently in patients with neuroendocrine tumours (NETs), owing to the high sensitivity of positron emission tomography (PET) with Gallium-68-DOTA-somatostatin analogues (68Ga-SSA) and concomitant diagnostic computed tomography (CT). Our aim was to determine the prevalence of extra-abdominal metastases on 68Ga-DOTATOC-PET/CT in a cohort of patients with small intestinal (Si-NET) and pancreatic NET (Pan-NET), as well as that of pancreatic metastasis in patients with Si-NET. Among 2090 patients examined by 68Ga-DOTATOC-PET/CT at two tertiary referral centres, a total of 1177 patients with a history of Si- or Pan-NET, were identified. The most recent 68Ga-DOTATOC-PET/CT report for each patient was reviewed, and the location and number of metastases of interest were recorded. Lesions outside the liver and abdominal nodes were found in 26% of patients (n = 310/1177), of whom 21.5% (255/1177) were diagnosed with Si-NET and 4.5% (55/1177) Pan-NET. Bone metastases were found in 18.4% (215/1177), metastases to Virchow's lymph node in 7.1% (83/1177), and lung/pleura in 4.8% (56/1177). In the subset of 255 Si-NET patients, 5.4% (41/255) manifested lesions in the pancreas, 1.5% in the breast (18/255), 1.3% in the heart (15/255) and 1% in the orbita (12/255). In Si-NET patients, the Ki-67 proliferation index was higher in those with ≥2 metastatic sites of interest, than with 1 metastatic site, (p <0.001). Overall, extra-abdominal or pancreatic metastases were more often found in patients with Si-NET (34%) than in those with Pan-NET (13%) (p <0.001). Bone metastases were 2.6 times more frequent in patients with Si-NET compared to Pan-NET patients (p <0.001). Lesions to the breast and orbita were encountered in almost only Si-NET patients. In conclusion, lesions outside the liver and abdominal nodes were detected in as many as 26% of the patients, with different prevalence and metastatic patterns in patients with Si-NET compared to Pan-NET. The impact of such metastases on overall survival and clinical decision-making needs further evaluation.

Efficacy and safety of neoadjuvant therapy in gastroenteropancreatic neuroendocrine neoplasms: A systematic review and meta-analysis.

OBJECTIVE: To determine the effectiveness and safety of neoadjuvant therapy in gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) and provide evidence-based suggestions for clinical treatment. METHODS: The Cochrane Library, Embase, PubMed, and Web of Science were searched for articles published that analyzed the effectiveness and safety of GEP-NEN-targeted neoadjuvant therapy before March 2023. A confidence interval (CI) of 95%, a subgroup analysis, heterogeneity, and effect size (ES) were analyzed, and a meta-analysis of the literature was performed using the Stata BE17 software. RESULTS: A total of 417 patients from 13 studies were included in this meta-analysis. The primary variables comprised the objective response rate (ORR), disease control rate (DCR), surgical resection rate, and R0 resection rate with ES values of 0.42 (95% CI: 0.25-0.60), 0.96 (95% CI: 0.93-0.99), 0.67 (95% CI: 0.50-0.84), and 0.60 (95% CI: 0.54-0.67), respectively. The secondary variables were the incidence rates of treatment-related adverse events (TRAEs), Grade 3 or higher TRAEs, and surgical complications with ES values of 0.29 (95% CI: -0.03-0.21), 0.13 (95% CI: -0.07-0.33), and 0.35 (95% CI: 0.27-0.44), respectively. CONCLUSION: Neoadjuvant therapy is an effective and safe treatment method for GEP-NENs. However, further studies are required to determine the optimal regimen for this therapy in these tumors.

From the archives of MD Anderson Cancer Center: Monomorphic epitheliotropic intestinal T-cell lymphoma: A case with an unusual immunophenotype and discussion of differential diagnosis.

Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is a rare and aggressive T-cell neoplasm associated with poor survival. We report a case of MEITL that presented as an ulcerated mass in the jejunum with perforation. Microscopic examination showed that the neoplasm involved the full thickness of the intestinal wall, extended into the mesentery, and was composed of monomorphic, small to medium-size cells. Immunohistochemical analysis showed that the neoplastic cells were positive for T-cell receptor (TCR) delta, CD3, CD7, CD8 (small subset), BCL-2 and TIA-1, and negative for TCR beta, CD4, CD5, CD10, CD20, CD30, CD34, CD56, CD57, CD99, ALK, cyclin D1, granzyme B, MUM1/IRF4, and TdT. The Ki-67 proliferation index was approximately 50 %. In situ hybridization for Epstein-Barr virus-encoded RNA (EBER ISH) was negative. Next-generation sequencing (NGS) analysis showed mutations involving SETD2 and STAT5B. The patient was treated with aggressive chemotherapy and consolidative autologous stem cell transplant and had clinical remission, but relapsed after about one year. Retreatment led to another one-year interval of clinical remission, but at last follow up the patient has relapsed disease involving the ileum and colon. We also discuss the differential diagnosis of MEITL.

SIRT4 loss reprograms intestinal nucleotide metabolism to support proliferation following perturbation of homeostasis.

The intestine is a highly metabolic tissue, but the metabolic programs that influence intestinal crypt proliferation, differentiation, and regeneration are still emerging. Here, we investigate how mitochondrial sirtuin 4 (SIRT4) affects intestinal homeostasis. Intestinal SIRT4 loss promotes cell proliferation in the intestine following ionizing radiation (IR). SIRT4 functions as a tumor suppressor in a mouse model of intestinal cancer, and SIRT4 loss drives dysregulated glutamine and nucleotide metabolism in intestinal adenomas. Intestinal organoids lacking SIRT4 display increased proliferation after IR stress, along with increased glutamine uptake and a shift toward de novo nucleotide biosynthesis over salvage pathways. Inhibition of de novo nucleotide biosynthesis diminishes the growth advantage of SIRT4-deficient organoids after IR stress. This work establishes SIRT4 as a modulator of intestinal metabolism and homeostasis in the setting of DNA-damaging stress.

Expression and clinical value of CXCR4 in high grade gastroenteropancreatic neuroendocrine neoplasms.

Background: CXC chemokine receptor 4 (CXCR4) is associated with the progression and metastasis of numerous malignant tumors. However, its relationship with Gastroenteropancreatic Neuroendocrine Neoplasms Grade 3 (GEP-NENs G3) is unclear. The aim of this study was to characterize the expression of CXCR4 in GEP-NENS and to explore the clinical and prognostic value of CXCR4. Methods: This study retrospectively collected clinical and pathological data from patients with GEP-NENs who receiving surgery in Qilu Hospital of Shandong University from January 2013 to April 2021, and obtained the overall survival of the patients based on follow-up. Immunohistochemistry (IHC) was performed on pathological paraffin sections to observe CXCR4 staining. Groups were made according to pathological findings. Kaplan-Meier (K-M) curve was used to evaluate prognosis. SPSS 26.0 was used for statistical analysis. Results: 100 GEP-NENs G3 patients were enrolled in this study. There was a significant difference in primary sites (P=0.002), Ki-67 index (P<0.001), and Carcinoembryonic Antigen (CEA) elevation (P=0.008) between neuroendocrine tumor (NET) G3 and neuroendocrine carcinoma (NEC). CXCR4 was highly expressed only in tumors, low or no expressed in adjacent tissues (P<0.001). The expression level of CXCR4 in NEC was significantly higher than that in NET G3 (P=0.038). The K-M curves showed that there was no significant difference in overall survival between patients with high CXCR4 expression and patients with low CXCR4 expression, either in GEP-NEN G3 or NEC (P=0.920, P=0.842. respectively). Conclusion: Differential expression of CXCR4 was found between tumor and adjacent tissues and between NET G3 and NEC. Our results demonstrated that CXCR4 can be served as a new IHC diagnostic indicator in the diagnosis and differential diagnosis of GEP-NENs G3. Further studies with multi-center, large sample size and longer follow-up are needed to confirm the correlation between CXCR4 expression level and prognosis.

Emergent approach to small bowel tumors: diagnosis and treatment.

BACKGROUND: This study presents the diagnosis and treatment of rare small bowel tumors through clinical cases. METHODS: Patients treated between 2000 and 2023 were included in the study. The clinical records of the patients were analyzed retrospectively. RESULTS: A total of 34 patients were included in the study. Of these patients, 26 (75.5%) were male and eight (23.5%) were female. The mean age of the patients was 62.1 years. The most common symptoms and signs were abdominal pain (76.4%), bloating (38.2%), and nausea and vomiting (17.6%). Diagnostic methods included computed tomography (CT) (82.3%), upper gastrointestinal double balloon enteroscopy (35.2%), and capsule endoscopy (5.8%). Diagnoses included adenocarcinoma in 13 cases, gastrointestinal stromal tumors (GISTs) in 12 cases, and neuroendocrine tumors (NETs) in two cases. CONCLUSION: Small bowel tumors frequently present with abdominal pain, bloating, and nausea and vomiting. CT and endoscopic procedures are the primary diagnostic tools. Small bowel cancers are often diagnosed late due to subtle clinical findings and the limitations of endoscopic imaging. Targeted screening strategies may be beneficial for certain at-risk and symptomatic patient groups. Early surgical intervention offers significant advantages for diagnosed patients.

Lymph node metastases are more frequent in paediatric appendiceal NET ≥1.5 cm but without impact on outcome - Data from the German MET studies.

BACKGROUND: Paediatric appendiceal neuroendocrine tumours (appNET) are very rare tumours, mostly detected incidentally by histopathological evaluation after appendectomy. Treatment recommendations are based on adult data considering high-risk NET as defined by European Neuroendocrine Tumour Society (ENETS) guidelines for completion right-sided hemicolectomy (RHC). Recent data suggest that less aggressive therapy may be justified. PROCEDURE: Analysis of children and adolescents with appNET prospectively registered with the German Malignant Endocrine Tumour (MET) studies between 1997 and 2022. RESULTS: By December 2022, 662 patients (64.7% females, 35.3% male) had been reported. Median age was 13.3 years [4.5-17.9], median duration of follow-up 2.2 years [0-10.9]. No distant metastases were reported. Tumour size was <1 cm in 63.5%, 1-2 cm in 33.2%, and >2 cm in 3.2% of patients. WHO grade 1 and 2 tumours were diagnosed in 76.9% and 23.1% of patients, respectively. Lymphovascular invasion and lymph node metastases were associated with tumour size ≥1.5 cm. 27.0% of patients presented with high-risk NET according to ENETS criteria. Of those, only 55.9% underwent secondary oncological right hemicolectomy. Neither distant metastases, nor recurrences or disease-related deaths occurred in patients with appendectomy only as well as in patients with completion RHC. Overall and event-free survival were both 100%. CONCLUSIONS: Internationally harmonized consensus recommendations on treatment of children and adolescents with appendiceal NET are urgently needed to avoid completion RHC in high-risk patients.

Prognostic factors for liver metastasis in patients with small intestinal stromal tumor: A retrospective analysis of surveillance, epidemiology, and end results.

BACKGROUND: Liver metastasis (LIM) is the most common distant site of metastasis in small intestinal stromal tumors (SISTs). The aim of this study was to determine the risk and prognostic factors associated with LIM in patients with SISTs. METHODS: Patients diagnosed with gastrointestinal stromal tumors between 2010 and 2019 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate logistic regression models, as well as a Cox regression model were used to explore the risk factors associated with the development and prognosis of LIM. Additionally, the overall survival (OS) of patients with LIM was analyzed using the Kaplan-Meier method. Furthermore, a predictive nomogram was constructed, and the model's performance was evaluated using receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA). RESULTS: A total of 1582 eligible patients with SISTs were included, among whom 146 (9.2%) were diagnosed with LIM. Poor tumor grade, absence of surgery, later T-stage, and no chemotherapy were associated with an increased risk of developing LIM. The nomogram prediction model achieved an AUC of 0.810, 95% Confidence Interval (CI) 0.773-0.846, indicating good performance, and the calibration curve showed excellent accuracy in predicting LIM. The OS rate of patients with LIM was significantly lower than that of patients without LIM (p < 0.001). CONCLUSIONS: Patients with SISTs who are at high risk of developing LIM deserve more attention during follow-up, as LIM can significantly affect patient prognosis. The nomogram demonstrated good calibration and discrimination for predicting LIM.

Fulminant ectopic Cushing's syndrome caused by metastatic small intestine neuroendocrine tumour - a case report and review of the literature.

Cushing's syndrome (CS) secondary to adrenocorticotropic hormone (ACTH) producing tumours is a severe condition with a challenging diagnosis. Ectopic ACTH-secretion often involves neuroendocrine tumours (NET) in the respiratory tract. ACTH-secreting small intestine neuro-endocrine tumours (siNET) are extremely rare entities barely reported in literature. This review is illustrated by the case of a 75-year old woman with fulminant ectopic CS caused by a ACTH-secreting metastatic siNET. Severe hypokalemia, fluid retention and refractory hypertension were the presenting symptoms. Basal and dynamic laboratory studies were diagnostic for ACTH-dependent CS. Extensive imaging studies of the pituitary and thorax-abdomen areas were normal, while [68Ga]Ga-DOTATATE PET-CT revealed increased small intestine uptake in the left iliac fossa. The hypercortisolism was well controlled with somatostatin analogues, after which a debulking resection of the tumour was performed. Pathological investigation confirmed a well-differentiated NET with sporadic ACTH immunostaining and post-operative treatment with somatostatin analogues was continued with favourable disease control.

Risk factors, prognostic factors, and nomograms for distant metastases in patients with gastroenteropancreatic neuroendocrine tumors: a population-based study.

Background: Patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs) have a poor prognosis for distant metastasis. Currently, there are no studies on predictive models for the risk of distant metastasis in GEP-NETs. Methods: In this study, risk factors associated with metastasis in patients with GEP-NETs in the Surveillance, Epidemiology, and End Results (SEER) database were analyzed by univariate and multivariate logistic regression, and a nomogram model for metastasis risk prediction was constructed. Prognostic factors associated with distant metastasis in patients with GEP-NETs were analyzed by univariate and multivariate Cox, and a nomogram model for prognostic prediction was constructed. Finally, the performance of the nomogram model predictions is validated by internal validation set and external validation set. Results: A total of 9145 patients with GEP-NETs were enrolled in this study. Univariate and multivariate logistic analysis demonstrated that T stage, N stage, tumor size, primary site, and histologic types independent risk factors associated with distant metastasis in GEP-NETs patients (p value < 0.05). Univariate and multivariate Cox analyses demonstrated that age, histologic type, tumor size, N stage, and primary site surgery were independent factors associated with the prognosis of patients with GEP-NETs (p value < 0.05). The nomogram model constructed based on metastasis risk factors and prognostic factors can predict the occurrence of metastasis and patient prognosis of GEP-NETs very effectively in the internal training and validation sets as well as in the external validation set. Conclusion: In conclusion, we constructed a new distant metastasis risk nomogram model and a new prognostic nomogram model for GEP-NETs patients, which provides a decision-making reference for individualized treatment of clinical patients.