Delayed Metastatic Cholangiocarcinoma to the Stomach With Imaging Characteristics Resembling Gastrointestinal Stromal Tumor: A Case Report and Review of the Literature

Intrahepatic cholangiocarcinoma (ICC) is a relatively rare subtype of cholangiocarcinoma, and there has been an increasing incidence of ICC in Western countries in recent years. Surgical resection is the most effective treatment for ICC. However, overall outcomes are extremely poor given that most patients are diagnosed at an advanced stage, and postoperative ICC recurrence is still very high despite hepatic resection. We report a case of metastatic ICC to the stomach presenting after resection of the original tumor, with imaging characteristics highly resembling gastrointestinal stromal tumor (GIST) on imaging. Reported cases of metastatic ICC to the liver are sparse. Given that there is a significant difference in the survival rate between metastatic cholangiocarcinoma and other tumors arising from the gastrointestinal tract, including GISTs, it is important to delineate the differences via imaging features. We further discuss the imaging characteristics of intrahepatic ICC, comparing and contrasting it to other gastric tumors.

Development of a CT image analysis-based scoring system to differentiate gastric schwannomas from gastrointestinal stromal tumors

Purpose

To develop a point-based scoring system (PSS) based on contrast-enhanced computed tomography (CT) qualitative and quantitative features to differentiate gastric schwannomas (GSs) from gastrointestinal stromal tumors (GISTs).

Methods

This retrospective study included 51 consecutive GS patients and 147 GIST patients. Clinical and CT features of the tumors were collected and compared. Univariate and multivariate logistic regression analyses using the stepwise forward method were used to determine the risk factors for GSs and create a PSS. Area under the receiver operating characteristic curve (AUC) analysis was performed to evaluate the diagnostic efficiency of PSS.

Results

The CT attenuation value of tumors in venous phase images, tumor-to-spleen ratio in venous phase images, tumor location, growth pattern, and tumor surface ulceration were identified as predictors for GSs and were assigned scores based on the PSS. Within the PSS, GS prediction probability ranged from 0.60% to 100% and increased as the total risk scores increased. The AUC of PSS in differentiating GSs from GISTs was 0.915 (95% CI: 0.874-0.957) with a total cutoff score of 3.0, accuracy of 0.848, sensitivity of 0.843, and specificity of 0.850.

Conclusions

The PSS of both qualitative and quantitative CT features can provide an easy tool for radiologists to successfully differentiate GS from GIST prior to surgery.

Imaging of pediatric abdominal soft tissue tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

This paper provides imaging recommendations for pediatric abdominal tumors that arise outside of the solid viscera. These tumors are rare in children and have been categorized in two groups: abdominal wall and peritoneal tumors (desmoid tumor and desmoplastic small round cell tumor) and tumors that arise from the gastrointestinal tract (gastrointestinal stromal tumor and gastrointestinal neuroendocrine tumor). Authors offer consensus recommendations for imaging assessment of these tumors at diagnosis, during follow-up, and when off-therapy.

Myosin Light-Chain Kinase Inhibition Potentiates the Antitumor Effects of Avapritinib in PDGFRA D842V-Mutant Gastrointestinal Stromal Tumor

PURPOSE

To create an in vivo model of PDGFRA D842V-mutant gastrointestinal stromal tumor (GIST) and identify the mechanism of tumor persistence following avapritinib therapy.

EXPERIMENTAL DESIGN

We created a patient-derived xenograft (PDX) of PDGFRA D842V-mutant GIST and tested the effects of imatinib, avapritinib, and ML-7, an inhibitor of myosin light-chain kinase (MYLK). Bulk tumor RNA sequencing and oncogenic signaling were evaluated. Apoptosis, survival, and actin cytoskeleton were evaluated in GIST T1 cells and isolated PDX cells in vitro. Human GIST specimens were analyzed for MYLK expression.

RESULTS

The PDX was minimally responsive to imatinib but sensitive to avapritinib. Avapritinib therapy increased tumor expression of genes related to the actin cytoskeleton, including MYLK. ML-7 induced apoptosis and disrupted actin filaments in short-term cultures of PDX cells and decreased survival in GIST T1 cells in combination with imatinib or avapritinib. Combined therapy with ML-7 improved the antitumor effects of low-dose avapritinib in vivo. Furthermore, MYLK was expressed in human GIST specimens.

CONCLUSIONS

MYLK upregulation is a novel mechanism of tumor persistence after tyrosine kinase inhibition. Concomitant MYLK inhibition may enable the use of a lower dose of avapritinib, which is associated with dose-dependent cognitive side effects.

Clinical Importance of Tumor Rupture in Gastrointestinal Stromal Tumor

Risk factors of gastrointestinal stromal tumors (GISTs) include tumor size, location, mitosis, and tumor rupture. Although the first three are commonly recognized as independent prognostic factors, tumor rupture is not a consistent finding. Indeed, tumor rupture may be subjectively diagnosed and is rarely observed. Moreover, the criteria used for diagnosis differ among oncologists, which may result in inconsistent outcomes. Based on these conditions, a universal definition of tumor rupture was proposed in 2019 and was consists of six scenarios: tumor fracture, blood-staining ascites, gastrointestinal perforation at the tumor site, histologically proven invasion, piecemeal resection, and open incisional biopsy. Although the definition is considered appropriate for selection of GISTs with worse prognostic outcomes, each scenario lacks a high level of evidence and there is yet no consensus for some, including histological invasion and incisional biopsy. It may be, however, important to have common criteria for clinical decision-making, which may facilitate reliability, external validity and comparability of clinical studies in rare GISTs. After the definition, several retrospective reports indicated that even with adjuvant therapy, tumor rupture was associated with high recurrence rates and poor prognostic outcomes. The prognosis of patients with ruptured GISTs is improved by 5-year adjuvant therapy compared with 3-year therapy. Nevertheless, the universal definition requires further evidence, and prospective clinical studies based on the definition are warranted. This article is protected by copyright. All rights reserved.

A novel technique for endoscope progression in gastroscopy resection: forward-return way for dissection of stromal tumor in the muscularis propria of the gastric fundus

Background

The fundus of the stomach is a challenging region for endoscopic resection of gastrointestinal stromal tumors (GISTs), especially in the anterior wall of the fornix at the side of the greater curvature. This study aimed to introduce the Forward-Return Way (FRW) technique in gastric fundus operations and provide evidence of its advantages. The FRW technique allows the gastroscope to access the stomach fornix without entering the gastric antrum after passing through the gastric cardia. Using FRW, the gastroscope body makes a forward return along the wall of the posterior wall of the upper gastric body and the wall of the greater curvature.

Methods

The clinical data of patients with stromal tumors in muscularis propria at the gastric fundus (STMF) at the Fourth Hospital of China Medical University between May 2020- March 2021 were reviewed. The novel FRW technique was used in the procedures, and the beneficial effects, suitability, applicable lesion site, and success rates of FRW were analyzed.

Results

A total of 10 cases were reviewed, and the FRW technique was successfully performed in 7 cases (70%). The gastroscope's tip reached the area just below the gastric cardia, allowing endoscopists to successfully access all angles and sites of the stomach's fundus in all seven patients. The lesion was easily accessed, and the gastroscope was stable with good left-right and forward-backwards movements.

Conclusion

The FRW technique significantly facilitates the resection of the GISTs by aligning the endoscopy body movement direction with the observation direction. Gastrointestinal Stromal Tumor; forward-return of gastroscopy along the gastric body wall; muscularis propria; gastric fundus.

Small bowel intussusception in an adult secondary to gastrointestinal stromal tumor: a rare case report

Intussusception is a rare surgical condition in adults less commonly confined to small bowel. Adult intussusception is an indication of surgical resection due to possibility of ischemia and malignant pathological cause like gastrointestinal stromal tumor (GIST) as in this case.

Case presentation

A 32-year-old male presented with abdominal pain and vomiting for 3 days. Vitals parameters and abdominal examinations were normal. Abdominal ultrasonography revealed target sign suggesting ileoileal intussusception in right lower quadrant. Abdominal contrast-enhanced computed tomography of abdomen showed features suggestive of ileoileal intussusception. Diagnostic laparoscopy was done which was later turned to laparotomy for segmental resection and anastomosis of ileum for ileoileal intussusception. Polypoidal growth noted in the resected section of ileum was found to be GIST (CD117 and DOG-1 positive) which was considered to be the lead point. Patient recovered well during postoperative period and later referred to oncology clinic for chemotherapy.

Clinical discussion

Intussusception and subsequent obstruction are very uncommon presentation in a patient with GIST because of their tendency to grow in an extraluminal fashion. As intussusception is rare in adult, high level of suspicion and proper imaging technique plays important role in diagnosing the condition.

Conclusion

Ileoileal intussusceptions due to GIST are a rare clinical entity in adult intussusceptions and generally have a vague variable clinical presentation thus requiring high index of clinical judgement and suspicion with judicious use of imaging.

Precision Oncology in Gastrointestinal Stromal Tumors

GIST (gastrointestinal stromal tumors) represent 20% of sarcomatous tumors and 1-2% of primary gastrointestinal cancers. They have an excellent prognosis when localized and resectable, though their prognosis is poor in the metastatic setting, with limited options after the second line until recently. Four lines are now standard in KIT-mutated GIST and one in PDGFRA-mutated GIST. An exponential growth of new treatments is expected in this era of molecular diagnostic techniques and systematic sequencing. Currently, the main challenge remains the emergence of resistance linked to secondary mutations caused by selective pressure induced by TKIs. Repeating biopsies to tailor treatments might be a step in the right direction, and liquid biopsies at progression may offer a non-invasive alternative. New molecules with wider KIT inhibition are under investigation and could change the catalog and the sequence of existing treatments. Combination therapies may also be an approach to overcome current resistance mechanisms. Here, we review the current epidemiology and biology of GIST and discuss future management options, with an emphasis on genome-oriented therapies.

Development and Validation of Artificial-Intelligence-Based Radiomics Model Using Computed Tomography Features for Preoperative Risk Stratification of Gastrointestinal Stromal Tumors

BACKGROUND

preoperative risk assessment of gastrointestinal stromal tumors (GISTS) is required for optimal and personalized treatment planning. Radiomics features are promising tools to predict risk assessment. The purpose of this study is to develop and validate an artificial intelligence classification algorithm, based on CT features, to define GIST's prognosis as determined by the Miettinen classification.

METHODS

patients with histological diagnosis of GIST and CT studies were retrospectively enrolled. Eight morphologic and 30 texture CT features were extracted from each tumor and combined to obtain three models (morphologic, texture and combined). Data were analyzed using a machine learning classification (WEKA). For each classification process, sensitivity, specificity, accuracy and area under the curve were evaluated. Inter- and intra-reader agreement were also calculated.

RESULTS

52 patients were evaluated. In the validation population, highest performances were obtained by the combined model (SE 85.7%, SP 90.9%, ACC 88.8%, and AUC 0.954) followed by the morphologic (SE 66.6%, SP 81.8%, ACC 76.4%, and AUC 0.742) and texture (SE 50%, SP 72.7%, ACC 64.7%, and AUC 0.613) models. Reproducibility was high of all manual evaluations.

CONCLUSIONS

the AI-based radiomics model using a CT feature demonstrates good predictive performance for preoperative risk stratification of GISTs.

Efficacy of post-first-line agents for advanced gastrointestinal stromal tumors following imatinib failure: A network meta-analysis

BACKGROUND

Imatinib is the standard first-line treatment for advanced gastrointestinal stromal tumors (GISTs); however, most patients eventually develop imatinib resistance, leading to considerable clinical challenges. Few direct comparisons have been made between different post-first-line therapies on clinical efficacy in advanced GIST following imatinib failure.

METHODS

Databases including PubMed, Embase, Scopus, Google Scholars, and Cochrane Library from inception to February 2023 were retrieved for randomized controlled trials evaluating the clinical efficacy of different post-first-line agents for advanced GIST following imatinib failure. Network and conventional meta-analysis were carried out using Stata/MP 16.0.

RESULTS

Ripretinib showed significant improvement in progression-free survival (PFS) rates from the 2nd to the 12th month compared to placebo, while there was virtually no evidence that the rest active agents had a significant benefit at the 12th month. Masitinib, ripretinib, sunitinib, regorafenib, and pimitespib exhibited significantly longer median PFS than placebo, and pairwise comparisons indicated there were no significant differences among masitinib, ripretinib, and sunitinib. These post-first-line agents decreased the risk of disease progression or death by 65% (HR = 0.35, 95% CI: 0.26-0.47) compared to placebo. Ripretinib and sunitinib came into effect earlier and exhibited more consistent overall survival (OS) rate improvements than masitinib and pimitespib, while pairwise comparisons revealed no significant differences in these four active agents concerning the improvement in OS rate. These post-first-line agents decreased the risk of death by 39% (HR = 0.61, 95% CI: 0.44-0.83) over placebo for advanced GIST following imatinib failure.

CONCLUSION

The active agents in our analysis as post-first-line therapies are able to provide superior clinical efficacy, with improved PFS rate and OS rate at certain time points, as well as absolute values of PFS and OS for advanced GIST. Ripretinib might be the optimal recommendation as a post-first-line treatment for advanced GIST following imatinib failure.

Risk factors for conversion from endoscopic resection to laparoscopic resection for gastric gastrointestinal stromal tumors

OBJECTIVE

Endoscopic resection (ER) of gastric gastrointestinal stromal tumors (gGISTs) is a commonly used treatment; however, it is associated with a risk of conversion to laparoscopic resection (LR). This study was performed to identify factors influencing conversion from ER to LR and the effects of conversion on outcomes.

METHODS

The clinicopathological features of patients treated for gGISTs from March 2010 to May 2021 were retrospectively collected. Endpoints included the determination of risk factors associated with LR conversion, with comparisons of surgical outcomes with and without conversion. Propensity score matching was performed to compare the two groups.

RESULTS

In total, 371 gGISTs were analyzed. Sixteen patients required conversion from ER to LR. Propensity score matching demonstrated that invasion depth (muscularis propria with exophytic growth) and gGIST size (≥3 cm) were independent risk factors for conversion to LR. The procedure duration (median, 160.5 vs. 60.0 minutes), postoperative hospitalization duration (median, 8 vs. 6 days), and postoperative fasting duration (median, 5 vs. 3 days) were significantly longer in patients who underwent conversion to LR.

CONCLUSIONS

Accurate preoperative measurements of tumor size and invasion depth may help determine more appropriate surgical approaches for patients with gGISTs.

Can EUS-FNA cytology reliably classify gastric submucosal spindle cell tumors?

BACKGROUND

Cytological diagnosis using endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for gastric submucosal spindle cell tumors, such as gastrointestinal stromal tumors (GISTs), leiomyomas, and schwannomas, is challenging because of their similar morphological characteristics.

OBJECTIVE AND MATERIALS

To clarify the cytological differential points, we reviewed the EUS-FNA cytology specimens of GISTs (37 cases), leiomyomas (11 cases), and schwannomas (4 cases).

METHOD

Twelve cytomorphological features were evaluated: lymphocytes, crushed nuclei, naked spindle nuclei, mast cell, length of the streaming arrangement, cellularity, nuclei at the cluster margin (nuclei located at the periphery of the cell cluster), peripheral feathering (loosely aggregated cells at the margin of a cell cluster tended to taper like feathers), metachromasia, wavy nuclei, fishhook-type nuclei, and anisonucleosis.

RESULTS

Among these features, lymphocytes, naked spindle nuclei, length of the streaming arrangement, cellularity, nuclei at the cluster margins, peripheral feathering, and anisonucleosis were statistically significant for differentiation. Based on these findings, we developed an algorithm for cytodiagnosis. The algorithm was taught to four cytologists, and the interobserver agreement and correct diagnosis rates were compared before and after education, which showed a significant improvement.

DISCUSSION

The histological types of gastric submucosal spindle cell tumors can be estimated using this algorithm for EUS-FNA cytology. Furthermore, this algorithm can be applied for cytological diagnosis at bedside during rapid on-site evaluation.

A Giant Solid-Cystic Gastric Inflammatory Myofibroblastic Tumor: A Case Report and Literature Review

An inflammatory myofibroblastic tumor (IMT) is a very rare tumor of mesenchymal origin with unclear etiopathogenesis, no unique diagnostic features, and no specific management protocol. It is often confused with inflammatory pseudotumor in literature, and the distinction needs further study. The average size, recurrence risk, and metastatic potential differ as per the site of origin. The abdomen is a very rare site for IMTs. Hepatic IMTs (H-IMTs) are reported to be solid tumors with sizes ranging from 1 cm to 20 cm in literature, and gastric IMTs (G-IMTs) range from 3 cm to 10 cm in size and can be solid-cystic. We report here a case of a 36-year-old gentleman with a 34x27x17 cm solid-cystic lesion in the lesser sac with loss of fat planes with stomach and left hemi-liver. The patient was managed by complete surgical resection of the lesion with wedge gastrectomy and wedge hepatectomy and recovered uneventfully. To our knowledge and based on our literature review, this case presents the largest reported and solid-cystic G-IMT with the involvement of left hemi-liver in a young gentleman and discusses its management as well as the relevant literature on this rare entity. This clinical presentation of G-IMT should be kept in the differential diagnosis in a relevant case presenting in the future. Immunohistochemistry is a must to establish the diagnosis, and surgical resection to negative margins is the management option of choice in resectable cases.

KIT A502_Y503 duplication mutation serves as a potential and universal target for neoantigen peptide in Chinese GIST patients

BACKGROUND AND AIM

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor with high prevalence of KIT and PDGFRA mutations. Few effective treatments can be exploited in imatinib or sunitinib resistant cases. While in immunotherapy, application of the highly individualized cancer neoantigen vaccines is hampered due to high economic and time cost. In this study we identified the most frequent mutation in Chinese GIST patients and predicted candidate neopeptide by next generation sequencing (NGS).

METHODS

Tumor tissues and matched blood samples of 116 Chinese GIST patients were collected. Genomic profile was detected through NGS, and 450 cancer genes were deeply sequenced. KIT mutations were identified, and long peptides containing the mutation were queried in NetMHCpan 4.0 tools to predict MHC class I binding of mutant peptides.

RESULTS

The most frequent mutated genes in detected GIST patients were KIT (81.9%, 95/116), CDKN2A (18.97%, 22/116), and CDKN2B (15.52%, 18/116) in this cohort. The most common mutation of KIT was A502_Y503 duplication (15.93%, 18/113) in exon 9. Among the 116 cases, 103 were HLA I genotyped, and 101 were HLA II genotyped. In total, 16 samples with the mutation of KIT p.A502_Y503dup were identified to produce neoantigens with qualified HLA affinity.

CONCLUSIONS

KIT hotspot mutation (p.A502_Y503dup) has the highest incidence, which may further eliminate the need for whole genome sequencing and patient-specific neoantigen prediction and synthesis. Therefore, for those carrying such mutation, accounting for around 16% of Chinese GIST patients and are usually less sensitive to imatinib, effective immunotherapies are in prospect.

Gastrointestinal Stromal Tumor in the Excluded Gastric Remnant After Roux-en-Y Gastric Bypass

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the GI tract. Despite this, they rarely occur, accounting for only 1% to 3% of all gastrointestinal tumors. This report describes a 53-year-old female patient with surgical history of Roux-en-Y gastric bypass (RYGB) who presented with right upper quadrant abdominal pain. CT imaging revealed a large 20 × 12 × 16 cm mass in the excluded stomach remnant. Ultrasound-guided biopsy confirmed this mass to be a GIST. The patient was treated surgically with exploratory laparotomy with distal pancreatectomy, partial colectomy, partial gastrectomy, and splenectomy. There are currently only 3 known reported cases of GISTs after RYGB.

Peculiar Presentation of Gastrointestinal Stromal Tumor in a Patient With Early Satiety

Gastrointestinal stromal tumors (GISTs) are one of the most common, potentially malignant, subepithelial lesions identified in the gastrointestinal tract. Hypothesized to derive from the interstitial cells of Cajal (ICC), GISTs commonly demonstrate gain of function mutations in proto-oncogenic receptor tyrosine kinase CD117 (KIT). Depending on mitotic activity and tumor size characteristics, GISTs may transform from benign to malignant neoplasms. Increasing evidence suggests that early identification of a GIST is paramount for optimal prognostic outcomes. We present a rare case of a GIST located in the uncinate pancreas identified via endoscopic ultrasound (EUS) and diagnosed with an EUS-guided fine needle aspiration (EUS-FNA) biopsy.

Exploration of a new method for Photoshop-assisted endoscopic ultrasound to distinguish gastrointestinal stromal tumor and leiomyoma

BACKGROUND

Gastrointestinal stromal tumors (GISTs) and leiomyomas (GILs) are difficult to be distinguished by endoscopic ultrasound (EUS). Photoshop software combined with EUS has limitations in distinguishing GIST and GIL by detecting gray values. Therefore, the research aims to explore the new method by Photoshop in distinguishing the features of GISTs from GILs.

METHODS

Patients who underwent EUS and were confirmed as GIST and GIL pathologically were included. The images of EUS were analyzed by Photoshop software. The mean gray value of tumor (Tmean), muscularis propria (Mmean), submucosa (Smean), water (Wmean) and T_SD that originated from the same image, were calculated one by one. Then the ratio of the mean gray value of tumor to muscularis propria (TMratio), submucosa (TSratio), and water (TWratio) were calculated, respectively.

RESULTS

Four hundred seventy-two patients (239 GILs and 233 GISTs) were enrolled in this study retrospectively. All the tumors were located in the stomach. Tmean and T_SD were significantly higher in GISTs than in the GILs group (63.10 ± 23.29 vs. 57.70 ± 22.67, p = .011; 26.24 ± 8.99 vs. 24.30 ± 8.26, p = .015). TMratio, TSratio, and TWratio were also significantly higher in GISTs group (0.97 ± 0.37 vs. 0.81 ± 0.28, p < .001; 0.42 ± 0.14 vs. 0.38 ± 0.12, p < .001; 2.65 ± 1.36 vs. 2.16 ± 1.02, p < .001). The AUC of Tmean was 0.952 (95% CI 0.897-1.000), which can better distinguish GIST from GIL; the sensitivity was 0.900, the specificity was 0.975, and the Youden Index was 0.875, and the cutoff was 79.64. The AUCs of TMratio, TSratio, and TWratio were 0.917 (95% CI 0.844-0.991), 0.897 (95% CI 0.812-0.981), and 0.929 (95% CI 0.8870-0.987), respectively. The aforementioned data was verified in the clinical cases of known results, including 40 GISTs and 40 GILs. The sensitivity of Tmean, TMratio, TSratio, and TWratio for diagnosis of GIL was 97.5%, 82.5%, 95%, and 97.5%, respectively. And they were 62.5%, 95%, 80%, and 92.5% for GIST.

CONCLUSION

The application of Photoshop combined with EUS to detect the gray value and standard deviation has a specific value in distinguishing GIST from GIL, but with some deviation. Applying the gray value ratio also has great discrimination significance and can avoid the differences in operation from different instrument and equipment personnel. Therefore, it is worthy of clinical promotion in the future.

A Fistulized Giant Duodenal Stromal Tumor in a Young Patient: A Case Report With Literature Review for Tomographic Diagnosis

BACKGROUND

Duodenal gastrointestinal stromal tumors (GISTs) are rare tumors of the gastrointestinal tract. It should be considered in the differential diagnosis of periampullary region pathologies.

CASE REPORT

A 24-year-old male patient applied to the general surgery department with the complaint of long-standing abdominal pain, nausea and vomiting after meals, and 8-10 kg weight loss in 1 month. Three-phase dynamic abdominopelvic CT showed that the 1st and the 2nd segments of the duodenum were dilated. At this level, a peripherally intensely contrasted heterogeneous mass lesion, 91x70x46 mm in size, was observed. There was oral contrast and air values in the center of the mass. A fistulized mass connected with the duodenal wall was considered in the differential diagnosis. In the surgical exploration, a soft, vascularized mass fistulized to the 2nd segment of the duodenum was observed. Pathological diagnosis was reported as GIST.

CONCLUSION

GISTs arise from the precursors of Cajal Interstitial cells of the gastrointestinal tract. Contrast-enhanced CT is the preferred diagnostic method for staging, risk stratification, and follow-up. We presented a young case with a giant duodenal GIST and discussed differential diagnosis and some diagnostic properties.

[Metachronous tumors of the stomach in a patient with autoimmune gastritis]

Stomach cancer continues to be a global health problem, ranking 5th among cancers and 4th among the causes of death from cancer in the world. Autoimmune atrophic gastritis is a chronic autoimmune disease characterized by the production of antibodies to parietal cells and intrinsic factor, followed by atrophy of the mucous membrane of the body and fundus of the stomach. Chronic autoimmune inflammation can lead to damage to the genetic apparatus of the cell and trigger a multi-stage process of carcinogenesis. Our article presents an unusual case of three different gastric tumors, including adenocarcinoma with microsatellite instability, in a patient with autoimmune gastritis.

Activity of Anlotinib in the Second-Line Therapy of Metastatic Gastrointestinal Stromal Tumors: A Prospective, Multicenter, In Vitro Study

BACKGROUND

Anlotinib is a multi-target tyrosine kinase inhibitor that can effectively inhibit tumor cell proliferation after receptor kinase activation caused by KIT gene mutation.

METHODS

We tested the inhibitory effect of anlotinib in GIST cell lines with different gene mutations and evaluated the efficacy of anlotinib for patients with metastatic GIST after imatinib failure in a multicenter, single-arm, phase II study.

RESULTS

In vitro, V654A mutation encoded by KIT exon 13 was intermediately sensitive to anlotinib. Moreover, anlotinib was able to partly suppress the activation loop mutation D820A from exon 17 while another activation loop mutation N822K, also from exon 17, was resistant to anlotinib. From September 2018 to October 2020, 64 patients from 9 Chinese medical centers were enrolled in this study. Seven patients had partial response and 39 patients had stable disease. The median PFS was 8.0 months. There was no statistical significance comparing with PFS of sunitinib second-line therapy at the same period. The most common adverse events related to anlotinib treatment were hypertension, neutropenia, and fatigue.

CONCLUSION

Anlotinib showed moderate antitumor activity in drug-resistant GIST cell lines in vitro, and good PFS and better tolerance in second-line therapy study.

An Unexpected GIST Causing Life-Threatening Bleeding after an Elective Hernia Repair

Background  Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the alimentary tract. They are usually manifested by GI bleeding. Case Presentation  A 53-year-old male patient was admitted to the hospital for elective inguinal hernia repair. The patient did not have any history of GI symptoms in the past. A day after open inguinal hernia repair, the patient developed recurrent attacks of hematemesis resulting in hemodynamic instability and admission to the intensive care unit. An upper GI endoscopy identified a small bleeding gastric lesion. After multiple failed attempts to control the bleeding endoscopically, an emergency exploratory laparotomy was performed. An unexpected large fungating bleeding gastric mass was detected. The mass measured approximately 40 × 30 cm, and multiple peritoneal deposits were also discovered. A wedge resection of the anterior gastric wall along with the mass was performed. Histopathology revealed a high-grade (G2) GIST. Discussion  GISTs appear in variable sizes and may lead to a variety of complications including abdominal pain, GI obstruction, and bleeding. This case highlights the unexpected presentation and sudden bleeding of a large GIST in a totally asymptomatic patient undergoing elective hernia surgery. It also illustrates that GIST can be asymptomatic and grow to large sizes before developing clinical manifestations. Conclusion  The case report highlights a common complication of GIST with unexpected timing, immediately after routine hernia surgery.

C-kit-negative transmural gastrointestinal stromal tumor in the stomach: A rare case of upper GI bleeding in Ghana

Upper GI bleeding from GIST is rare in Africa. The C-kit-negative variant is uncommon worldwide. We report a case of a 42-year-old woman managed for upper GI bleeding secondary to stomach GIST, negative for CD117 but positive for DOG 1 and CD 34. The 1-year postsurgery review is uneventful.

Corrigendum: Comparison of prognosis between microscopically positive and negative surgical margins for primary gastrointestinal stromal tumors: A systematic review and meta-analysis

[This corrects the article DOI: 10.3389/fonc.2022.679115.].

Synchronous cutaneous malignant peripheral nerve sheath tumor and jejunal gastrointestinal stromal tumor and submucosal angiomyolipoma in type 1 neurofibromatosis: A case report and literature review

RATIONALE

Type 1 neurofibromatosis (NF1) is one of the most prevalent genetic conditions. NF1 is characterized by cutaneous plexiform neurofibromas and café au lait skin pigmentation, and is inherited in an autosomal dominant trait with mutation in the neurofibromin 1 gene on chromosome 17. Neurofibromin is involved in Ras proto-oncogene regulation. Accordingly, NF1 may lead to malignancies, with a lifetime cancer risk of 60%. Malignant peripheral nerve sheath tumor (MPNST) is the leading cause of mortality due to NF1. The relevance of gastrointestinal stromal tumor (GIST) in NF1 is increasingly being reported in the literature and NF1-associated GIST has been identified to have an alternative molecular pathogenesis.

PATIENT CONCERNS

A 62-years-old female had a 7 × 5 cm growing back mass in the background of various sized cutaneous neurofibromas with café au lait spots. Computed tomography performed in the workup revealed a 4.1 cm enhancing mass near the ileal mesentery.

DIAGNOSES

NF1 affected by cutaneous MPNST of the back, and synchronous GIST and submucosal angiomyolipoma (AML) of the jejunum.

INTERVENTIONS

The patient underwent laparoscopic jejunal mass excision, and excision and flap coverage for the back mass owing to the suspicion of multiple MPNSTs. However, the abdominal masses were diagnosed as GIST and AML following confirmation of the immunohistochemical profiles. Accordingly, the patient was administered adjuvant radiotherapy to the MPNST after surgery.

OUTCOMES

Symptomatic improvements were achieved, and no subsequent relapses were observed.

LESSONS

Although MPNST and GIST are not rare neoplasm in NF1, only 2 case reports have been published on the synchronous occurrence of these tumors. Moreover, no case report has been published on AML in NF1, except 1 renal AML in segmental neurofibromatosis. Identifying the clinical and pathologic significances of the NF1 is important to achieve improved diagnostic accuracy.

Case report: Giant cystic ileal gastrointestinal stromal tumor with an atypical intratumoral abscess

Background

Gastrointestinal stromal tumors (GISTs) are typically solid, sometimes with small cystic areas, but rarely manifest as predominantly cystic neoplasms. In addition, cystic intestinal GISTs with intratumoral abscess formation are rare.

Case presentation

We present the case of a 49-year-old male patient with a history of frequent and urgent urination for 2 weeks. Radiologic studies revealed a large cystic mass in the lower abdomen. The patient underwent abdominal laparotomy, which revealed a large cystic mass arising from the distal ileum invading the sigmoid mesocolon and apex vesicae. Partial resection of the ileum along with the tumor and the adjacent bladder was performed. Macroscopic examination revealed that the cystic mass contained a large amount of foul-smelling pus and a tumor-bowel fistula. The final pathology revealed an abdominal stromal tumor. Postoperative recovery was uneventful, and adjuvant imatinib mesylate 400 mg was administered daily. No tumor recurrence or metastasis was observed during the 9-month follow-up period.

Conclusion

Fingings of a cystic tumor in the abdomen should raise concern for cystic GISTs. This case report reviews a rare presentation of an ileal giant cystic GIST with atypical intratumoral abscess formation. Complete surgical resection and adjuvant imatinib is still the mainstay treatment for GISTs.

Chinese Pedigree with Hereditary Gastrointestinal Stromal Tumors: A Case Report and Literature Review

Familial gastrointestinal stromal tumor (GIST) is a rare autosomal dominant genetic disorder with only a few affected families reported to date. Here, we report a case of familial GISTs harboring a novel germline mutation within exon 18 of KIT. A 58-year-old male patient presented with gastric subepithelial lesions accompanied by cutaneous hyperpigmentation, which were subsequently diagnosed as multinodular GISTs. Endoscopic surgery was initially conducted to remove the larger lesions, and pathological examinations were then conducted for the diagnosis of GISTs. Family history revealed that some other family members had similar cutaneous pigmentations. Whole-exome sequencing was used to search for potential driver mutations, and Sanger sequencing was used for mutation validation. A novel primary driver mutation of KIT (c.G2485C, p.A829P) was detected in these hereditary GISTs, which has been reported in some targeted chemotherapy-resistant GISTs. Cell models were subsequently established for the rapid screening of candidate drugs and exploring potential mechanisms. This mutation could lead to cell proliferation and imatinib resistance by ligand-independent activation of KIT; however, ripretinib administration was identified as an applicable targeted therapy for this mutation. The mutation activated the JAK/STAT3 and MAPK/ERK pathways, which could be inhibited by ripretinib administration. To the best of our knowledge, this is the first report of the KIT-A829P mutation in familial GISTs, complementing the pathogenesis of familial GISTs and providing valuable information for the precision treatment of this disease.

Incidentally Detected Gastrointestinal Stromal Tumor in a Patient with Carcinoma Prostate: 68Ga-Prostate-Specific Membrane Antigen Versus 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

Uptake of 68Ga-prostate-specific membrane antigen (PSMA) in various nonprostatic tumors is well documented in the literature. We present a case of a gastrointestinal stromal tumor, incidentally detected on 68Ga-PSMA positron emission tomography/computed tomography imaging in a patient who underwent imaging for a suspected recurrence of carcinoma prostate.

Gastrointestinal Stromal Tumor Recurrence Presenting as a Small Bowel Obstruction: A Case Report

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the alimentary tract in adults. The most common site is the stomach, followed by the small intestine. The clinical presentation varies from an incidental finding in asymptomatic patients to a large palpable mass causing complications such as bowel obstruction or viscus perforation. The best imaging modality is a CT scan of the abdomen. Treatment is determined by the size and location of the GISTs. Surgical intervention is considered for resectable tumors, while tyrosine kinase inhibitor therapy is considered for irresectable, metastatic, or recurrent GISTs. In this case report, we present a 30-year-old female who is a known case of gastric GIST and liver metastases. She presented to the emergency department with intestinal obstruction secondary to a recurrent GIST abdominal mass and underwent emergency laparotomy for mass resection. Following surgery, the patient developed aspiration pneumonia, which was treated with proper antibiotics. She was discharged in stable clinical condition with a recommendation to start alternative tyrosine kinase therapy. GISTs are difficult to diagnose preoperatively, as most patients are asymptomatic, and they may present with complications, as in our case, a small bowel obstruction. A proper imaging modality will guide the physician toward the diagnosis, but the final diagnosis will be achieved by biopsy. The diagnosis may be challenging, as small bowel obstruction has many causes, although GISTs should be kept in mind as one of the deferential diagnoses.

An Unusual Case of Suspected Metastatic Gastrointestinal Stromal Tumor Complicated by Streptococcus Intermedius Pyogenic Liver Disease

A gastrointestinal stromal tumor (GIST) is a mesenchymal neoplasm of the gastrointestinal tract often known to express c-KIT or platelet-derived growth factor receptor alpha (PDGFRα). Among all GI tract cancers, they account for less than 1% of cases. Most patients become symptomatic in the later stages of the tumor's course, often presenting with insidious anemia due to gastrointestinal bleeding and metastasis. The recommended management of solitary GIST is surgery, while larger or metastatic tumors that express c-KIT are managed with imatinib as either neoadjuvant or adjuvant therapy. Due to the progression of these tumors, they are at times associated with systemic anaerobic infection, which is an indication of malignancy workup. In this case report, we discuss a 35-year-old woman who was discovered to have GIST with possible hepatic metastasis complicated by pyogenic liver disease due to Streptococcus intermedius and the diagnostic challenge of differentiating between infection and tumor.

4-(Imidazo[1,2-a]pyridin-3-yl): pyrimidine derivatives as anticancer agents

A series of 4-(imidazo[1,2-a]pyridin-3-yl)-pyrimidine derivatives are claimed as inhibitors of c-KIT and as potential treatments for cancer. Their chemical preparation and biological evaluation against imatinib-resistant tumor cells have been described. Several claimed molecules have excellent IC50 values in the nanomolar range. Several molecules were also selective against a wide panel of kinases. Few specific inhibitors have been found to have promising oral bioavailability and acceptable to excellent values regarding the inhibition of hERG channel. This class represents a new platform for developing new anticancer treatment against a wide range of c-KIT mutations and secondary mutations that may arise in gastrointestinal stromal tumor patients.

Simple Scoring Model Based on Enhanced CT in Preoperative Prediction of Biological Risk of Gastrointestinal Stromal Tumor

Objective: To construct a simple scoring model for predicting the biological risk of gastrointestinal stromal tumors based on enhanced computed tomography (CT) features. Methods: The clinicopathological and imaging data of 149 patients with primary gastrointestinal stromal tumor were retrospectively analyzed in our hospital. According to the risk classification, the patients were divided into low-risk group and high-risk group. The features of enhanced CT were observed and recorded. Univariate and multivariate logistic regression models were used to determine the predictors of high-risk biological behaviors of gastrointestinal stromal tumor, and then a simple scoring model was constructed according to the regression coefficients of each predictor. The receiver operating characteristic curve was used to evaluate the predictive ability of the model. Results: There was no significant difference between the risk classification of gastrointestinal stromal tumor with gender and age (P = .168, .320), while significant difference was found between the tumor size and location (P < .001). Univariate and multivariate logistic regression analyses showed that tumor size, enlarged vessels feeding or draining the mass, peritumoral lymph node enlargement, and venous phase contrast enhancement rate were independent predictors of the biological risk of gastrointestinal stromal tumor (P < .05). The area under the curve value of tumor size, enlarged vessels feeding or draining the mass, peritumoral lymph node enlargement, and venous phase contrast enhancement rate as the high-risk predictor of gastrointestinal stromal tumor were 0.955, 0.729, 0.680, and 0.807, respectively. Receiver operating characteristic curve results showed that the area under the curve of the scoring model constructed based on enhanced CT features was 0.941 (95% confidence interval: 0.891-0.973). When the total score was >1, the sensitivity of the scoring model in diagnosing gastrointestinal stromal tumor was 85.58%, the specificity was 88.89%, the positive predictive value was 88.51%, the negative predictive value was 86.04%, and the accuracy was 86.18%. The results of DeLong test showed that the area under the curve of the scoring model was better than that of the receiver operating characteristic curve of tumor size, enlarged vessels feeding or draining the mass, peritumoral lymph node enlargement, venous phase contrast enhancement rate, and other indicators alone in predicting the high risk of gastrointestinal stromal tumor, and the differences were statistically significant (Z = 26.510, P < .001; Z = 3.992, P < .001; Z = 6.353, P < .001; Z = 4.052, P = .013). Conclusion: The simple scoring model based on enhanced CT features is a simple and practical clinical prediction model, which is helpful to make preoperative individualized treatment plan and improve the prognosis of gastrointestinal stromal tumor patients.

Transcriptomic study of gastrointestinal stromal tumors with liver metastasis

Introduction: GIST (gastrointestinal stromal tumor) is the most prominent mesenchymal neoplasms of the gastrointestinal tract, and liver is the most common metastasis site for GIST. The molecular mechanism leading to liver metastasis of GIST is currently unclear. Methods: With the goal of revealing the underlying mechanism, we performed whole-genome gene expression profiling on 18 pairs of RNA samples comprised of GIST tissues (with liver metastasis) and corresponding non-tumor tissues. After identifying differentially expressed gene, functional annotation and signal pathway analyses were conducted. GSE13861, datasets that compare GIST (without liver metastasis) with adjacent tissues, served as a comparison. Results: A total of 492 up-regulated genes and 629 down-regulated genes were identified as differentially expressed genes between liver metastasis tissues and non-tumor tissues. We characterized expression patterns of DEGs identified from our cohort and GSE13861 that show signatures of enrichment for functionality. In subsequent gene set enrichment analysis, differentially expressed genes were mainly enriched in Epithelial Mesenchymal Transition in both datasets. 493 genes were overlapped among our whole-genome gene expression profiling results and GSE13861, consisting 188 up-regulated genes and 305 down-regulated genes. By using CytoHubba plugin of Cytoscape, CDH1, CD34, KIT, PROM1, SOX9, FGF2, CD24, ALDH1A1, JAG1 and NES were identified as top ten hub genes in tumorigenesis and liver metastasis of GIST. higher expression levels of FGF2, JAG1, CD34, ALDH1A1 and the lower expression level of CDH1 were respectively associated with unfavorable overall survival. Meanwhile higher expression levels of CD34, FGF2, KIT, JAG1, ALDH1A were correlated with worse disease-free survival. Discussion: The present study may help to provide candidate pathways and targets for treatment of GIST and prevention methods to liver metastasis.

GISTs with NTRK Gene Fusions: A Clinicopathological, Immunophenotypic, and Molecular Study

The most common mutations in gastrointestinal stromal tumors (GISTs) are KIT or PDGFRA mutations. Recently, neurotrophic tyrosine receptor kinase (NTRK) fusions have been reported in WT GISTs, which increased interest in introducing tropomyosin receptor kinase (TRK) inhibitors as treatments for GISTs with NTRK fusions. Hence, we aimed to screen NTRK fusions in WT GISTs; we used fluorescence in situ hybridization (FISH), next-generation sequencing (NGS), and immunohistochemistry (IHC) to screen NTRK fusions in 46 WT GISTs and evaluate each method. We further reviewed NTRK fusion-positive GISTs from the literature and performed clinical and pathological analyses; two GISTs with an ETV6-NTRK3 fusion (5%) were identified, while only one (50%) was positive for Pan-TRK expression. On the other hand, among the six GISTs with Pan-TRK-positive expression, only one (17%) harbored NTRK fusion. The literature review revealed the strong consistency between FISH and NGS and the limited value of Pan-TRK IHC in screening NTRK fusions in GISTs. In addition, the clinical and pathological analysis showed that GISTs with NTRK rearrangement occurred less frequently in the stomach, were more frequently larger in size, and the epithelioid type presented with a higher risk of recurrence. The NTRK3 fusion has been more common than the NTRK1 fusion in GISTs to date; our study identified two ETV6-NTRK3 fusions in 46 WT GISTs. Compared with FISH and IHC, NGS is preferred for screening WT GISTs, including NTRK rearrangements. However, since GISTs with NTRK fusions are rare, further studies including more samples and mechanistic investigations should be conducted in the future.

Small Gastric Stromal Tumors: An Underestimated Risk

BACKGROUND AND OBJECTIVES

Small gastrointestinal stromal tumors (GISTs) are defined as tumors less than 2 cm in diameter, which are often found incidentally during gastroscopy. There is controversy regarding the management of small GISTs, and a certain percentage of small GISTs become malignant during follow-up. Previous studies which used Sanger targeted sequencing have shown that the mutation rate of small GISTs is significantly lower than that of large tumors. The aim of this study was to investigate the overall mutational profile of small GISTs, including those of wild-type tumors, using whole-exome sequencing (WES) and Sanger sequencing.

METHODS

Thirty-six paired small GIST specimens, which were resected by endoscopy, were analyzed by WES. Somatic mutations identified by WES were confirmed by Sanger sequencing. Sanger sequencing was performed in an additional 38 small gastric stromal tumor samples for examining hotspot mutations in KIT, PDGFRA, and BRAF.

RESULTS

Somatic C-KIT/PDGFRA mutations accounted for 81% of the mutations, including three novel mutation sites in C-KIT at exon 11, across the entire small gastric stromal tumor cohort (n = 74). In addition, 15% of small GISTs harbored previously undescribed BRAF-V600E hotspot mutations. No significant correlation was observed among the genotype, pathological features, and clinical classification.

CONCLUSIONS

Our data revealed a high overall mutation rate (~96%) in small GISTs, indicating that genetic alterations are common events in early GIST generation. We also identified a high frequency of oncogenic BRAF-V600E mutations (15%) in small GISTs, which has not been previously reported.

Neurofibromatosis type 1 in Syrian older patient presented with gastric outlet obstruction

Neurofibromatosis type 1 is an autosomal dominant disorder with cutaneous features and multiple tumors that involve different organs. Gastrointestinal stromal tumors are non-epithelial tumors associated with neurofibromatosis type 1 and arise from the gastrointestinal tract. Patients with gastrointestinal stromal tumor present most commonly with anemia due to overt or occult bleeding and in rare cases diagnosis might be delayed so patients present with gastrointestinal tract obstruction. Here, we report a rare case of an older patient with neurofibromatosis type 1, who was undiagnosed and presented with acute abdomen due to gastric outlet obstruction. It was caused by progressive gastrointestinal stromal tumor in the antrum of the stomach. Gastrointestinal stromal tumors should be considered in the differential diagnosis of gastric outlet obstruction, especially in patients with neurofibromatosis type 1.

Ki-67 index assessment on FNA specimens of gastrointestinal stromal tumor: Correlation with mitotic rate and potential predictive value for risk stratification

BACKGROUND

Risk assessment of gastrointestinal stromal tumor (GIST) is challenging on cytology specimens. This study aims to determine whether Ki-67 index evaluated on fine-needle aspiration (FNA) specimens can correlate with the mitotic rate of GIST in surgical specimens and provide further risk assessment.

METHODS

Cases with cell blocks containing adequate tumor cells and surgical resections were included. Ki-67 immunostain was retrospectively performed on cell block sections, and Ki-67 index was calculated on the "hot spot" areas.

RESULTS

This study included 50 GIST cases from stomach (n = 45; 90%), duodenum (n = 4; 8%), and distal esophagus (n = 1; 2%). The tumor size ranged from 1.5 cm to 21 cm (mean, 5.4 cm). Based on the mitotic count, 37 GISTs (74%) had low mitotic rate (LMR) and 13 GISTs (26%) had high mitotic rate (HMR). The spindle cell, epithelioid, and mixed types accounted for 60%, 14%, and 26% of GIST, respectively. Ki-67 index counted on cell block sections correlated well with mitotic count evaluated in surgical specimens (r = 0.8031). Mean Ki-67 index was higher in HMR than LMR groups (3.5% vs. 1%, p < .001). The receiver operating characteristic curve using Ki-67 index to predict mitotic rate was further analyzed, and area under the curve was 0.839. Using a cutoff of 2.5% yielded a sensitivity of 70% at 92% specificity.

CONCLUSIONS

This study demonstrates good correlations between Ki-67 index and mitotic count or risk stratification, suggesting that Ki-67 index evaluated on cytology specimens may offer a promising approach to preoperatively predict the mitotic rate and risk of GIST.

Diagnostic Dilemma: Parasitic Ovarian Fibroma With Degeneration

An ovarian fibroma is a rare entity and a diagnostic dilemma due to its solid nature and ultrasound findings being similar to a uterine fibroid. An ovarian fibroma, being parasitic, is extremely rare. We report the case of a 35-year-old, multiparous woman who presented with a 'wandering' abdominal mass of six months duration. Clinical examination revealed a 16-week size, solid, firm, well-defined mass in the right lumbar and iliac regions, separate from the uterus on bimanual examination, suggestive of a pedunculated subserous fibroid uterus. Ultrasound abdomen with color Doppler evaluation was suggestive of the non-uterine origin of the tumor, probably a gastrointestinal stromal tumor. In view of the diagnostic dilemma, MRI was done, which showed that the lesion had features characteristic of ovarian fibroma, however, bilateral ovaries were normally visualized. An exploratory laparotomy was performed. There was a solid parasitic tumor adherent to the bladder peritoneum and attached to the right ovary by a thin band, which was excised. Histopathology confirmed ovarian fibroma. To conclude, a parasitic ovarian fibroma is rare and a careful clinical approach with imaging and surgery helps in solving this diagnostic dilemma.

Ileal gastrointestinal stromal tumor presenting as retroperitoneal mass

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal (GI) tract. It represents a wide range of clinical tumors with different clinical presentations, locations, and prognoses. Retroperitoneal GISTs are rarely seen and may be associated with the GI system. In this case report, we present the laparoscopic excision of retroperitoneal ileal GIST in a patient who was admitted to the outpatient clinic with abdominal pain.

Gastric Antral Gastrointestinal Stromal Tumor Presenting With Severe Anemia

Gastrointestinal stromal tumors are rare gastrointestinal tract growths associated with high rates of malignant transformation. Most cases are asymptomatic and can be identified by computed tomography scan. We present the case of a 50-year-old male with melena and fatigue. Endoscopy showed an ulcerated submucosal tumor diagnosed as a gastrointestinal stromal tumor after surgical resection; it did not present with metastasis and was successfully treated surgically without relapse.

Aspartate and Acetate Fuel Gastrointestinal Stromal Tumors Beyond the Warburg Effect

Metabolic reprogramming is closely linked to the tumorigenesis and drug resistance of gastrointestinal stromal tumors (GISTs). Mapping the metabolic orbit of GISTs is a prerequisite if intervention against the metabolic vulnerability of refractory GISTs is desirable.

Methods

A total of 43 patients with treatment-naïve GISTs who had undergone surgical resections were enrolled, on whom a metabolomics profile detected from surgical specimens was constructed based on the 1H-nuclear magnetic resonance (NMR) platform. The mRNA and protein levels of GLUT1, HK2, ACSS2, and FASN were assayed. Dual-tracer 18F-FDG/11C-acetate PET imaging was introduced before surgery in 15 patients.

Results

1H-NMR-based metabolomics revealed that GISTs were characterized by upregulation of glutamate, ascorbate, aspartate and glycine and downregulation of choline, creatine, glucose and glycerol. Bioinformatics analysis showed that the TCA cycle and alanine, aspartate, and glutamate metabolism were the two leading pathways. High- and nonhigh-risk (including intermediate-, low-, and very low-risk) GISTs preferentially displayed upregulation of HK2 and ACSS2, respectively, echoed by in vivo imaging that high- and nonhigh-risk GISTs preferentially exhibited higher uptake of 18F-FDG and 11C-acetate, respectively, while 18F-FDG and 11C-acetate were complementary to each other. Nuclear ACSS2 was exclusively identified in high-risk GISTs.

Conclusion

We describe a metabolic landscape of GISTs that read aspartate as a de facto "oncometabolite," which was replenished via the TCA cycle and alanine, aspartate, and glutamate metabolism. Glycolysis and ACSS2-mediated acetate metabolism competed and complemented fatty acid synthesis, although glycolysis remained an aggressive phenotype.

The Prognostic Value of Plasma Programmed Death Protein-1 (PD-1) and Programmed Death-Ligand 1 (PD-L1) in Patients with Gastrointestinal Stromal Tumor

BACKGROUND

This study investigates the prognostic value of plasma Programmed Death Protein-1 (PD-1) and Programmed Death-Ligand 1 (PD-L1) concentrations in patients with Gastrointestinal Stromal Tumor (GIST).

METHODS

Patients with GIST were included (n = 157) from the two Danish sarcoma centers, independent of disease- and treatment status. The patients were divided into three subgroups; 1: patients with localized disease who underwent radical surgery; 2: patients with local, locally advanced, or metastatic disease; and 3: patients without measurable disease who had undergone radical surgery. Sensitive electrochemiluminescence immune-assays were used to determine PD-1 and PD-L1 concentration in plasma samples. The primary endpoint was the PFS.

RESULTS

No patients progressed in group 1 (n = 15), 34 progressed in group 2 (n = 122), and three progressed in group 3 (n = 20). Significantly higher plasma concentrations of PD-1 (p = 0.0023) and PD-L1 (0.012) were found in patients in group 2 compared to PD-1/PD-L1 levels in postoperative plasma samples from patient group 1. Patients with active GIST having a plasma concentration of PD-L1 above the cutoff (225 pg/mL) had a significantly poorer prognosis compared to patients with plasma PD-L1 concentration below the cutoff.

CONCLUSIONS

Plasma PD-L1 shows potential as a prognostic biomarker in patients with GIST and should be further evaluated.

Deep learning and radiomics to predict the mitotic index of gastrointestinal stromal tumors based on multiparametric MRI

Introduction

Preoperative evaluation of the mitotic index (MI) of gastrointestinal stromal tumors (GISTs) represents the basis of individualized treatment of patients. However, the accuracy of conventional preoperative imaging methods is limited. The aim of this study was to develop a predictive model based on multiparametric MRI for preoperative MI prediction.

Methods

A total of 112 patients who were pathologically diagnosed with GIST were enrolled in this study. The dataset was subdivided into the development (n = 81) and test (n = 31) sets based on the time of diagnosis. With the use of T2-weighted imaging (T2WI) and apparent diffusion coefficient (ADC) map, a convolutional neural network (CNN)-based classifier was developed for MI prediction, which used a hybrid approach based on 2D tumor images and radiomics features from 3D tumor shape. The trained model was tested on an internal test set. Then, the hybrid model was comprehensively tested and compared with the conventional ResNet, shape radiomics classifier, and age plus diameter classifier.

Results

The hybrid model showed good MI prediction ability at the image level; the area under the receiver operating characteristic curve (AUROC), area under the precision-recall curve (AUPRC), and accuracy in the test set were 0.947 (95% confidence interval [CI]: 0.927-0.968), 0.964 (95% CI: 0.930-0.978), and 90.8 (95% CI: 88.0-93.0), respectively. With the average probabilities from multiple samples per patient, good performance was also achieved at the patient level, with AUROC, AUPRC, and accuracy of 0.930 (95% CI: 0.828-1.000), 0.941 (95% CI: 0.792-1.000), and 93.6% (95% CI: 79.3-98.2) in the test set, respectively.

Discussion

The deep learning-based hybrid model demonstrated the potential to be a good tool for the operative and non-invasive prediction of MI in GIST patients.

A systematic review and network meta-analysis of the efficacy and safety of third-line and over third-line therapy after imatinib and TKI resistance in advanced gastrointestinal stromal tumor

Tyrosine kinase inhibitors (TKIs) have greatly improved the prognosis of unresectable and metastatic gastrointestinal stromal tumors (GISTs) in the last two decades. Imatinib and sunitinib are recommended as first-line and second-line therapies, respectively. However, there is a lack of precision therapy for refractory GISTs regarding therapy after imatinib and sunitinib. We comprehensively searched electronic databases, including PubMed, EMBASE, Web of Science, Cochrane Library, and ClinicalTrials, from inception to October 2022. Randomized controlled trials featuring comparisons with third-line or over third-line therapies against GISTs were eligible. The primary outcome was progression-free survival (PFS). All network calculations were performed using random effect models, and the ranking of regimens were numerically based on the surface under the cumulative ranking (SUCRA) statistics. A total of seven studies were eligible for inclusion in this network meta-analysis. After analysis, ripretinib was ranked at the top in progression-free survival (PFS), overall survival (OS), and disease control rate (DCR) (SUCRA statistics: 83.1%, 82.5%, and 86.5%, respectively), whereas nilotinib and pimitespib presented better tolerability (SUCRA statistics: 64.9% and 63.8%, respectively). We found that regorafenib seemed more reliable for clinical administration, and ripretinib showed good effectiveness for the over third-line therapy. Precise targeted therapy is a critical direction for the future treatment of GIST, and more high-quality studies of new agents are expected.

A case report of gastrointestinal stromal tumor of the duodenum

INTRODUCTION

Gastrointestinal stromal tumors (GISTs) rarely occur in the duodenum, and only a few cases have been reported. Its clinical manifestations are not specific, and the imaging examination results are not typical, so a preoperative diagnosis is difficult. Pathologic examinations and genetic testing after surgical resection are the main diagnostic methods. Here, a case of duodenal stromal tumor complicated by gastrointestinal perforation is reported. A 57-year-old man presented with paroxysmal abdominal pain and bloating for 7 days. Contrast-enhanced computed tomography of the abdomen revealed a large mass (10 cm in diameter) in the right upper abdomen, which was considered neoplastic. The mass was anterior and inferior to the head of the pancreas, and medial to the mesenteric vessels. The tumor surrounded the descending and horizontal parts of the duodenum, and it ruptured into the lumen of the descending duodenum. After the patient underwent tumor resection, we found a rupture of the descending duodenal opening. After that, duodenal fistula drainage, gastrostomy, jejunostomy, small intestinal adhesion release and abdominal irrigation drainage were performed. Immunohistochemical staining results were as follows: CD34 (-), desmin (-), S-100 (-), CD117 (9.7) (+), DoG-1 (+), SDHB (+), Ki-67 (+5%). Based on these results, the lesion was finally diagnosed as duodenal GIST. The patient underwent surgical resection without targeted therapy and recovered well.

DISCUSSION

Duodenal stromal tumors often present with gastrointestinal bleeding and other clinical symptoms, requiring urgent surgery. Complete resection of the tumor is an effective surgical method. Extended resection does not prolong survival. However, surgical treatment should be determined according to the size and location of the tumor and its relationship to the pancreas. This highly malignant duodenal stromal tumor was >10 cm, accompanied by gastrointestinal perforation and necrosis. Surgical resection was required while protecting the organ function.

The value of contrast-enhanced harmonic endoscopic ultrasound in differential diagnosis and evaluation of malignant risk of gastrointestinal stromal tumors (<50mm)

OBJECTIVES

Contrast-enhanced harmonic endoscopic ultrasound (CEH-EUS) has been used in the differential diagnosis of benign and malignant tumors by visualization of tumor microcirculation and perfusion. However, its diagnostic role in submucosal tumors (SMTs), especially leiomyomas and gastric submucosal tumors (GISTs) was rarely studied. The aim of this study was to analyze the diagnostic role of CEH-EUS for SMTs (<50 mm) and the value of assessing the malignant potential of GISTs.

MATERIALS AND METHODS

We retrospectively included patients with tumors <50 mm in diameter who underwent preoperative EUS and CEH-EUS examination and had pathologically confirmed as leiomyomas and GISTs. To analyze the imaging features of CEH-EUS with pathological diagnosis as the gold standard and evaluate its diagnostic value.

RESULTS

This study included 10 cases of leiomyomas and 38 cases of GISTs. Under CEH-EUS detection, 86.9% of GISTs showed hyper-enhancement, 89.5% showed diffuse enhancement, 39.5% showed non-enhancing spots, and 97.4% showed obvious capsule enhancement. In contrast, the leiomyoma cases mostly showed hypo-enhancement (50.0%) or non-enhancement (30.0%) (p < 0.05). Then, the value of CEH-EUS in the differential diagnosis of benign and malignant tumors based on blood flow is significantly higher than that of B-EUS. Signal appearance time was significantly faster in the intermediate-high risk GISTs than in the very low-low risk group (5.1 s versus 15.5 s, p < 0.05), and the AUROC values predicted the risk at this time to be 0.903 (0.763-0.975). Heterogeneous perfusion and non-enhancing spots were also more common in the intermediate-high risk group. Univariate and multivariate analysis revealed that intratumoral irregularitie was an independent predictor of moderate to high risk (OR 3.99, 95%CI 1.04-90.95), with sensitivity, specificity and accuracy of 73.33%, 91.30% and 84.21%, respectively.

CONCLUSIONS

Through this study, CEH-EUS has a good differential diagnostic ability for leiomyomas and GISTs, and has a high value in predicting the risk of GISTs.

Endoscopic Ultrasound for Diagnosis and Management of Pediatric Gastrointestinal Stromal Tumor

Gastrointestinal (GI) stromal tumors arise from the interstitial cells of Cajal and are rare in the pediatric population. The most common clinical manifestation is anemia secondary to GI bleeding. Endoscopy is commonly used for diagnostic and therapeutic interventions of an obstructing mass or gastrointestinal bleed, while experience with endoscopic ultrasound (EUS) and EUS fine needle aspiration (EUS-FNA) for pediatric patients with suspected gastric tumors is limited. We report 2 cases, a 14-year-old male and an 11-year-old female, who presented with symptomatic anemia. Both patients were diagnosed with GI stromal tumors of the stomach using EUS and EUS-FNA. This report shows that EUS and EUS-FNA are safe and effective diagnostic tools for pediatric patients.

Current Molecular Profile of Gastrointestinal Stromal Tumors and Systemic Therapeutic Implications

Gastrointestinal stromal tumors (GISTs) are malignant mesenchymal tumors arising from the intestinal pacemaker cells of Cajal. They compose a heterogenous group of tumors due to a variety of molecular alterations. The most common gain-of-function mutations in GISTs are either in the KIT (60-70%) or platelet-derived growth factor receptor alpha (PDGFRA) genes (10-15%), which are mutually exclusive. However, a smaller subset, lacking KIT and PDGFRA mutations, is considered wild-type GISTs and presents distinct molecular findings with the activation of different proliferative pathways, structural chromosomal and epigenetic changes, such as inactivation of the NF1 gene, mutations in the succinate dehydrogenase (SDH), BRAF, and RAS genes, and also NTRK fusions. Currently, a molecular evaluation of GISTs is imperative in many scenarios, aiding in treatment decisions from the (neo)adjuvant to the metastatic setting. Here, we review the most recent data on the molecular profile of GISTs and highlight therapeutic implications according to distinct GIST molecular subtypes.

Latest Advances in the Management of Pediatric Gastrointestinal Stromal Tumors

Gastrointestinal stromal tumor is the most common mesenchymal neoplasm of the gastrointestinal tract, usually found in elderly adults. It is infrequent among pediatric patients and usually differs biologically from adult-type diseases presenting mutations of KIT and PDGFR genes. In this population, more frequent is the wild-type GIST possessing SDH, TRK, RAS, NF1 mutations, among others. Both tumor types require individualized treatment with kinase inhibitors that are still being tested in the pediatric population due to the different neoplasm biology. We review the latest updates to the management of pediatric gastrointestinal tumors with a particular focus on the advances in molecular biology of the disease that enables the definition of possible resistance. Emerging treatment with kinase inhibitors that could serve as targeted therapy is discussed, especially with multikinase inhibitors of higher generation, the effectiveness of which has already been confirmed in the adult population.

Clinicopathological characteristics of gastric IgG4-related disease: Systematic scoping review

BACKGROUND AND AIM

Gastric IgG4-related disease (IgG4-RD) can mimic malignancy, submucosal tumors (SMT), and ulcers, leading to over-triage and unnecessary medical interventions such as gastrectomy. The variability in the clinicopathological presentation of IgG4-related disease is not yet well defined, posing a diagnostic challenge.

METHODS

Following the PRISMA Extension for Scoping Reviews, we searched MEDLINE and EMBASE for all peer-reviewed articles using keywords including "gastritis," "stomach," "gastrointestinal stromal tumor," and "IgG4-RD" from their inception to December 28, 2021.

RESULTS

Thirty-nine articles, including 2 observational studies and 42 cases, were included in the systematic review. While bottom-heavy lymphoplasmacytic mucosal infiltration is a characteristic finding of gastric IgG4-RD, it was only present in less than half of the patients in the observational studies. Patients with gastric IgG4-RD were more likely to be diagnosed with gastrointestinal stromal tumor (GIST), gastric cancer, or peptic ulcer disease and their clinical course involved resection (51.3%) or even gastrectomy. Diagnosis of gastric IgG4-RD was most frequently made by post-operative pathological analysis.

CONCLUSION

This systematic review summarizes the current understanding of the characteristics of gastric IgG4-RD. Increased awareness of gastric IgG4-RD as a differential diagnosis of gastric SMT or ulcers among clinicians is crucial in order to reduce unnecessary high-risk, invasive interventions.

A jejunal gastrointestinal stromal tumor with massive gastrointestinal hemorrhage treated by emergency surgery: A case report

BACKGROUND

A jejunal gastrointestinal stromal tumor (GIST) is a rare neoplasm of the gastrointestinal (GI) tract. Massive bleeding due to a jejunal GIST is a diagnostic and therapeutic challenge. It may be a life-threatening GIST complication that requires urgent intervention. Acute GI bleeding, which requires urgent surgical intervention, is a very rare clinical manifestation of GIST. A jejunal GIST with massive hemorrhage with coronavirus disease 2019 in a male patient in older age with many comorbidities has been not reported in the worldwide literature.

METHODS

In this case report, we present an 80-year-old man who was admitted to surgery due to abdominal pain, melena, and hematochezia for several hours. An upper endoscopy and colonoscopy were inconclusive. A multidetector contrast-enhanced computed tomography (CT) of the abdominal and pelvic cavity showed concentric irregular thickening in the distal jejunum.The histopathological finding showed a GIST measuring 6 cm with a mitotic index 2/50 high power fields. The patient's hemodynamic condition deteriorated despite initial conservative treatment including a blood transfusion. Therefore, patient underwent the emergency surgery 24 hours after admission: partial jejunal resection with the tumor followed by primary end-to-end anastomosis.

RESULTS

The mass was removed completely. There were no surgical complications in the postoperative course. On the first postoperative day, a severe acute respiratory syndrome coronavirus 2 polymerase chain reaction test was performed due to a persistent dry cough, which yielded a positive result. After 14 days, the patient died due to pneumonia and circulatory failure.

CONCLUSIONS

This case indicates that jejunal GIST can present as massive lower gastrointestinal bleeding and urgent surgery can successfully stop bleeding and save the patient's life. The CT scan was the most effective investigation to find the source of GI bleeding in this case. Therefore, we suggest performing CT in patients with acute massive lower gastrointestinal bleeding when the source of bleeding is not visible on endoscopy, and urgent surgical jejunal resection to stop life-threatening bleeding caused by a jejunal GIST.