Endoscopic versus surgical resection in the management of gastric schwannomas.

BACKGROUND AND AIMS: Gastric schwannoma (GS) is not well clinically recognized and surgical resection (SR) remains the mainstay of treatment. Recently, endoscopic resection (ER) appears to be a safe and effective alternative. However, its comparative outcomes with SR is lacking. Our aim was to first compare clinical outcomes and costs between ER and SR in the management of GSs. METHODS: A total of 46 consecutive patients with GSs who underwent ER (n = 16) or SR (n = 30) in our large tertiary center between July 2007 and Oct 2018 were included. Clinicopathologic features, clinical outcomes, medical costs and follow-up were retrospectively reviewed and compared between two groups. RESULTS: Baseline characteristics are comparable except for a smaller tumor size in ER group (22.9 vs 41.0 mm, p = 0.002). Complete resection was achieved in 87.5% of patients with ER and 100% of patients with SR (p = 0.116). The ER group had a significant shorter operative time (91.6 vs 128.2 min), less blood loss (16.9 vs 62.7 mL) and lower operation cost (21,054.4 vs 30,843.4 RMB) than SR group (all p < 0.05). There was no significant difference in adverse events (12.5% vs 10%, p = 0.812) and length of postoperative hospital stay (8.3 vs 8.2 days, p = 0.945). During a long-term follow-up of mean 37.4 months (range 6-140 months), no residue, recurrence or metastasis was observed in both groups. CONCLUSIONS: Compared with SR, ER has the similar safety and efficacy in the management of GSs, but contributes to a shorter operation time and lower medical costs. ER may be considered as the first-line treatment, especially for patients with GSs smaller than 30 mm.

Gastric schwannoma with giant ulcer and lymphadenopathy mimicking gastric cancer: a case report.

BACKGROUND: Gastric schwannomas are rare benign tumors originating from the intramuscular plexus of the stomach and account for just 2.6% of gastric mesenchymal tumors. Gastric schwannoma (GS) with a surface ulcer is very rare. Herein, we report a rare case of an ulcer-bearing GS, which in conjunction with multiple enlarged regional lymph nodes, readily mimicked gastric cancer (GC). CASE PRESENTATION: A 79-year-old female presented with poor appetite and intermittent vomiting of gastric contents during the past month. Gastroscopy revealed a giant crateriform ulcer within the stomach body (at the angular notch). Its raised and indurated border was fragile and bled easily. GC was thus suspected. Contrast-enhanced computer tomography (CT) revealed a mild enhancement of the corresponding irregularly thickened gastric wall, and an annular zone of mucosal discontinuity. Enlarged regional lymph nodes were also found, making GC with metastases of lymph nodes our primary concern. 18F-fluorodeoxyglueose position emission tomography (18F-FDG PET)/CT was then performed for further staging. Obviously increased FDG uptake was shown in the gastric lesion ((maximum standardized uptake value (SUVmax) 14.6), but no FDG uptake was observed in the enlarged regional lymph nodes. Given the strong suspicion of GC, subtotal gastrectomy was performed. GS was revealed by postoperative pathology, with no evidence of metastasis in the 13 resected lymph nodes. CONCLUSIONS: This was a rare case of GS with a giant surface ulcer and multiple enlarged regional lymph nodes. The uptake of 18F-FDG in the tumor was substantially higher than previously published literature reports. Under these circumstances, it is difficult to be differentiated from GC.

Endoscopic submucosal excavation and endoscopic full-thickness resection for gastric schwannoma: five-year experience from a large tertiary center in China.

BACKGROUND AND AIMS: Endoscopic resection (ER) is an effective and safe method for gastric submucosal tumors, mostly composed of gastrointestinal stromal tumors and leiomyomas. The role of ER in gastric schwannoma (GS) has rarely been described. Our aim was to evaluate the efficacy and safety of ER for GS. METHODS: This is a retrospective study in consecutive patients who underwent ER for GS from March 2013 to October 2018 at our center. Clinicopathological, endoscopic, and follow-up data were collected and analyzed. RESULTS: A total of 16 consecutive patients (9 females, 56.3%) were included, with a mean age of 50.4 years (range 25-75 years). The mean tumor size was 22.9 ± 15.1 mm (range 10-55 mm). Thirteen tumors (81.3%) were located in the middle third of the stomach and 12 tumors (75%) grew with intraluminal pattern. Endoscopic submucosal excavation (ESE) was performed in 7 patients while endoscopic full-thickness resection (EFTR) was done in 9 patients. R0 resection was achieved in 14 patients (87.5%). The mean operative time was 91.6 ± 52.8 min (range 36-203 min) and the mean postoperative length of hospital stays was 8.3 ± 2.7 days (range 6-13 days). No adverse events were encountered except for fevers in 2 patients. No patients required surgical resection or intervention. During long-term follow-up of mean 21.8 months (range 6-62 months), no residue, recurrence, or metastasis was observed. CONCLUSIONS: ER is effective and safe for patients with GS with favorable long-term outcomes.

Endoscopic resection for gastric schwannoma with long-term outcomes.

BACKGROUND: Gastric schwannoma is not so recognized by clinicians as its counterparts. The efficacy of endoscopic resection has not been described yet. Our aim was to assess the efficacy and safety of endoscopic resection in the management of gastric schwannoma. METHODS: Retrospective data were reviewed from January 2008 to December 2013 in our center. Fourteen patients who had endoscopic resection with the final pathology result of gastric schwannoma were included in the study. RESULTS: Of the 14 patients, there were 12 females and two males. The median age was 59 years (range 32-83). Thirteen tumors (92.9 %) were from the muscularis propria and one located in the submucosa. Endoscopic en bloc resection was achieved in 12 patients (12/14, 85.7 %), including seven cases of endoscopic full-thickness resection (EFTR). The mean resected tumor size was 1.73 ± 1.10 cm (range 0.3-4.0 cm). In one case, endoscopic resection was suspended due to the limited experience of EFTR during the early period of the study. In another case, due to the difficult tumor location (gastric angle) and extraluminal growth pattern, the patient was referred to laparoscopic surgery. In the 12 successful endoscopic resection cases, during the median follow-up time of 4 years (range 17-77 months, one patient lost), no tumor residue, recurrence or metastasis was found. CONCLUSIONS: Endoscopic resection is safe and effective in treating gastric schwannoma with excellent long-term outcomes. However, it should be performed with caution because schwannoma is mainly located in the deep muscular layer, which leads to the full-thickness resection of gastric wall.

Gastric schwannoma: a case report.

Gastric schwannomas are rare mesenchymal tumors that arise from the intestinal nerve plexuses. They present with nonspecific symptoms and are often discovered incidentally. We present the case of a 68-year-old patient who had been suffering from abdominal discomfort for 6 months. After a complete examination, including abdominal computed tomography and upper gastrointestinal endoscopy, we discovered a submucosal gastric lesion with benign gross features without evidence of lymph node or metastatic involvement. He underwent an open laparotomy. Final pathohistological and immunohistochemically identification of the surgical specimen established the diagnosis of benign schwannoma. Considering the excellent prognosis of the tumor, no adjuvant treatment was suggested other than simple clinical monitoring every 6 months. Despite the accessibility of advanced endoscopy and imaging techniques, the diagnosis of gastric schwannoma is rarely made preoperatively. In the latter case, the best treatment is still complete excision with wide margins.

Gastric schwannoma: A retrospective analysis of clinical characteristics, treatments, and outcomes.

BACKGROUND: This study aimed to investigate the clinical characteristics, treatment options, and prognosis of patients with gastric schwannoma (GS). METHODS: Patients who were pathologically diagnosed with GS between April 2011 and October 2022 were enrolled. The data of clinical characteristics, pathological features, treatment options, and clinical outcomes were collected and compared between GS patients who underwent endoscopic resection (ER) and surgical resection (SR). RESULTS: Of the 32 cases, 23 underwent SR and nine underwent ER. The median tumor size was significantly smaller in ER group than in SR group (12.0 vs. 40.0 mm, P < 0.001), while patients in SR group were older than those in ER group (54.5 ± 10.6 vs. 45.3 ± 10.9 years, P = 0.036). Moreover, tumors in ER group were more likely to exhibit an intraluminal pattern (100% vs. 26.1%, P < 0.001). Patients in ER group had significantly lower hospitalization cost (25859.2 ± 8623.9 vs. 44953.0 ± 13083.8 RMB, P = 0.011) than those in SR group. No differences were found between the two groups in terms of R0 resection rate, operative time, estimated blood loss, adverse events, and recurrence rate. All patients were followed up for 4-96 months (mean: 35 months; median: 23 months), during which no evidence of recurrence or metastasis was observed. CONCLUSIONS: Both ER and SR are safe and effective treatment modalities for the management of GS, with ER being associated with lower medical costs compared to SR. The majority of GS are benign and do not recur, with little possibility of malignant transformation.

Gastric Schwannoma-Two Unusual Cases with Usual Presentation and Review of Literature.

Schwannomas, also known as neurilemmomas, are characteristically benign, slow growing neoplasms originating from Schwann cell sheath. Gastrointestinal schwannomas are very rare with stomach being the most affected organ representing approximately 0.2% of all gastric tumours. Malignant transformation is rarely reported in these tumors and complete surgical resection with negative margins is the recommended treatment. Herein, we report our experience of 2 cases of gastric submucosal spindle cell tumour (SMT), which were preoperatively assumed to be as gastrointestinal stromal tumor (GIST), however postoperatively confirmed as schwannoma on immunohistochemical examination.

Preoperative differentiation of gastric schwannomas and gastrointestinal stromal tumors based on computed tomography: a retrospective multicenter observational study.

Introduction: Gastric schwannoma is a rare benign tumor accounting for only 1-2% of alimentary tract mesenchymal tumors. Owing to their low incidence rate, most cases are misdiagnosed as gastrointestinal stromal tumors (GISTs), especially tumors with a diameter of less than 5 cm. Therefore, this study aimed to develop and validate a diagnostic nomogram based on computed tomography (CT) imaging features for the preoperative prediction of gastric schwannomas and GISTs (diameters = 2-5 cm). Methods: Gastric schwannomas in 47 patients and GISTs in 230 patients were confirmed by surgical pathology. Thirty-four patients with gastric schwannomas and 167 with GISTs admitted between June 2009 and August 2022 at Hospital 1 were retrospectively analyzed as the test and training sets, respectively. Seventy-six patients (13 with gastric schwannomas and 63 with GISTs) were included in the external validation set (June 2017 to September 2022 at Hospital 2). The independent factors for differentiating gastric schwannomas from GISTs were obtained by multivariate logistic regression analysis, and a corresponding nomogram model was established. The accuracy of the nomogram was evaluated using receiver operating characteristic and calibration curves. Results: Logistic regression analysis showed that the growth pattern (odds ratio [OR] 3.626; 95% confidence interval [CI] 1.105-11.900), absence of necrosis (OR 4.752; 95% CI 1.464-15.424), presence of tumor-associated lymph nodes (OR 23.978; 95% CI 6.499-88.466), the difference between CT values during the portal and arterial phases (OR 1.117; 95% CI 1.042-1.198), and the difference between CT values during the delayed and portal phases (OR 1.159; 95% CI 1.080-1.245) were independent factors in differentiating gastric schwannoma from GIST. The resulting individualized prediction nomogram showed good discrimination in the training (area under the curve [AUC], 0.937; 95% CI, 0.900-0.973) and validation (AUC, 0.921; 95% CI, 0.830-1.000) datasets. The calibration curve showed that the probability of gastric schwannomas predicted using the nomogram agreed well with the actual value. Conclusion: The proposed nomogram model based on CT imaging features can be used to differentiate gastric schwannoma from GIST before surgery.

Gastric schwannoma: The gastrointestinal tumor simulator - case report and review of the literature.

INTRODUCTION AND IMPORTANCE: Gastric schwannoma is a rare and benign tumor originating from the peripheral nerves of the stomach. Despite its benign nature, this tumor typically remains asymptomatic for an extended period, and its radiological and endoscopic presentation poses challenges in distinguishing it from other gastric mesenchymal tumors. CASE PRESENTATION: Here, we present a rare case of a patient experiencing gastric pain and melena secondary to a gastric mass. The initial preoperative diagnosis indicated a gastrointestinal stromal tumor, but subsequent pathological and immunohistochemical staining of the surgical specimen confirmed the presence of gastric schwannoma. DISCUSSION: To gain insights into this uncommon condition, we conducted an electronic search on PubMed using the keywords "gastric schwannoma" and "gastric neurinoma." Our focus centered on case series containing more than five cases of gastric localization, resulting in the analysis of 14 case series involving a total of 321 patients. Our review aims to comprehensively discuss the clinical, radiological, and therapeutic aspects associated with this rare disease. CONCLUSION: In the absence of a definitive preoperative diagnosis, the surgical approach is considered the primary treatment for resectable gastric schwannoma, given its excellent long-term outcomes. However, further studies are imperative to better define the role of endoscopic resection in managing this condition.

Common Benign Nerve Sheath Tumor at an Uncommon Location - Gastric Schwannoma.

Gastric schwannomas are rare types of gastrointestinal mesenchymal tumours that are slow-growing and mostly benign. They are usually asymptomatic. In some cases, nonspecific gastric symptoms, palpable mass, and bleeding can be seen. A definitive diagnosis requires pathological and immunohistochemical examination, and surgical resection offers an excellent prognosis with uncommon recurrence. We present a case of a 62-year-old woman who underwent exploratory laparotomy and wedge resection with preoperative diagnosis as gastrointestinal stromal tumor and postoperatively diagnosed as schwannoma on histopathology.

Gastric Schwannoma in an Octogenarian: A Case Report and Review of the Literature.

Gastric schwannomas are an exceedingly rare tumor arising from the myenteric plexus of the gastrointestinal enteric nervous system. These schwannomas are most commonly benign and reported to occur in female patients with a mean age of 58 at presentation. They are most often discovered incidentally, but can occasionally present with abdominal discomfort, obstructive symptoms, or GI bleeding. Frequently, the initial clinical consideration is for a gastrointestinal stromal tumor, which is much more common. A definitive diagnosis is made with microscopic imaging and immunohistochemical staining. Complete surgical resection, typically performed laparoscopically, is the most definitive and usually curative treatment, requiring no further follow-up. Herein, we present the first and only case of gastric schwannoma in an octogenarian and discuss an update on current diagnostic and therapeutic options.

A huge benign gastric schwannomas presented with upper and lower gastrointestinal bleeding: a case report and literature review.

Gastric schwannomas (GS) are rare mesenchymal tumors from Schwann cells in the gastrointestinal (GI) tract, representing 2-6% of such tumors. We report a 52-year-old woman who experienced abdominal pain, hematemesis, and melena, initially suspected of having a GI stromal tumor through ultrasound and computed tomography abdomen. Despite no active bleeding found during an upper endoscopy, she underwent a successful open subtotal gastrectomy, with histopathology confirming GS. The diagnosis of GS, which may mimic other GI conditions, relies heavily on imaging and histopathological analysis due to its nonspecific symptomatology, including the potential for both upper and lower GI bleeding. This case underscores the diagnostic challenges of GS and highlights surgical resection as the preferred treatment, generally leading to a favorable prognosis.

Gastric Schwannoma: A Rare Subepithelial Lesion of the Stomach.

Gastric schwannomas (GS) are rare, slow-growing, benign subepithelial (SE) lesions of the stomach. These are difficult to differentiate preoperatively from other types of SE lesions, as the gross appearance and clinical presentation are very similar especially the gastrointestinal stromal tumors (GISTs), which are the most common SE lesions of the stomach. We present the case of a 35-year-old Asian man with a one-month history of intermittent, right, upper quadrant pain and hematemesis. Preoperatively, intravenous contrast-enhanced computer tomography scan (CECT) showed a well-circumscribed lesion in the upper abdomen closer to the stomach's lesser curvature. Endoscopic ultrasound revealed an ulcerated subepithelial lesion and subsequent biopsy with a 22-gauge fine-needle biopsy (22G FNB) needle confirmed the diagnosis of GS. The patient underwent distal gastrectomy and a Bilroth 1 procedure. The postoperative biopsy was consistent with the initial one, therefore supporting the diagnosis of gastric schwannoma. Postoperatively, the recovery remained uneventful.

Schwannoma: A Rare Case of Submucosal Gastric Tumor.

Schwannoma is a tumor that originates from the Schwann cells that surround a neuron's axon. This tumor is very rare in the gastrointestinal tract and develops submucosally from intestinal nerve plexuses. The most common location for gastrointestinal schwannomas is the stomach, where they account for only 0.2% of gastric tumors. We present the case of a 56-year-old asymptomatic patient who was diagnosed, following a routine ultrasound examination, with an abdominal tumor. An abdominal MRI confirmed the gastric origin of the tumor. Although a subsequent upper-digestive endoscopic ultrasound was performed, a definitive diagnosis could not be established. Thus, a laparoscopic wedge resection of the stomach was performed. The immunohistochemical examination of the tumor established the diagnosis of benign schwannoma. Despite the availability of advanced endoscopy and imaging techniques, the diagnosis of gastric schwannoma is very rarely preoperative. The immunohistochemical identification of S-100 on the surgical specimen confirmed the diagnosis.

Machine learning-based predictive model for the differential diagnosis of ≤ 5 cm gastric stromal tumor and gastric schwannoma based on CT images.

The clinical symptoms of ≤ 5 cm gastric stromal tumor (GST) and gastric schwannoma (GS) are similar, but the treatment regimens are different. This study explored the value of computed tomography (CT) combined with machine learning (ML) algorithms to find the best model to discriminate them. A total of 126 patients with GST ≤ 5 cm and 35 patients with GS ≤ 5 during 2013-2022 were included. CT imaging features included qualitative data (tumor location, growth pattern, lobulation, surface ulcer status, necrosis, calcification, and surrounding lymph nodes) and quantitative data [long diameter (LD); short diameter (SD); LD/SD ratio; degree of enhancement (DE); heterogeneous degree (HD)]. Patients were randomly divided into a training set (n = 112) and test set (n = 49) using 7:3 stratified sampling. The univariate and multivariate logistic regression analysis were used to identify independent risk factors. Five ML algorithms were used to build prediction models: Support Vector Machine, k-Nearest Neighbor, Random Forest, Extra Trees, and Extreme Gradient Boosting Machine. The analysis identified that HDv, lobulation, and tumor growth site were independent risk factors (P < 0.05). We should focus on these three imaging features of tumors, which are relatively easy to obtain. The area under the curve for the SVM, KNN, RF, ET, and XGBoost prediction models were, respectively, 0.790, 0.895, 0.978, 0.988, and 0.946 for the training set, and were, respectively, 0.848, 0.892, 0.887, 0.912, and 0.867 for the test set. The CT combined with ML algorithms generated predictive models to improve the differential diagnosis of ≤ 5 cm GST and GS which has important clinical practical value. The Extra Trees algorithm resulted in the optimal model.

Treatment of gastric paralysis after gastric schwannoma by electroacupuncture: A case report and literature review.

OBJECTIVE: We identified the potential role of electroacupuncture (EA) as an alternative therapy to traditional Chinese medicine (TCM) in a rare case of postoperative gastroparesis after gastric schwannoma (GS). CLINICAL PRESENTATION: A 31-year-old woman presented with impaired gastric emptying after gastrectomy for GS and was diagnosed with postoperative gastroparesis syndrome (PGS). The symptoms were slightly relieved after routine placement of the jejunal tube; however, symptoms such as dietary intolerance and impaired gastric emptying persisted. After the consultation, the patient agreed to undergo EA therapy. INTERVENTION AND RESULTS: The patient was able to tolerate oral intake after seven days of EA treatment, and the frequency and amount of food intake increased. The jejunal tube was removed at the outpatient follow-up two weeks after discharge, and the patient resumed a semi-liquid diet and was able to eat small amounts of rice. Reexamination of the upper digestive tract angiography showed that part of the contrast agent passed through the pyloric sinus, which showed improvement. CONCLUSION: EA stimulation increased tolerance to transoral feeding in patients with postoperative gastroparesis and facilitated the passage of contrast agents through the pyloric sinus. No adverse effects were observed during treatment, and the treatment was well accepted and tolerated by patients. A review article noted the benefits of acupuncture for gastrointestinal disorders but lacked high-quality evidence to support this.1 Therefore, the therapeutic role of EA needs to be further elucidated to provide high-quality evidence-based medical evidence for its clinical use.

Gastric schwannoma coexisting with tubular adenoma of the gallbladder: a rare combination.

We report a case of a man in his early 50 s who was admitted to our hospital for anorexia. An imaging examination led to a preoperative diagnosis of a gastrointestinal stromal tumor and gallbladder stones. He underwent treatment by laparoscopic cholecystectomy and distal partial gastrectomy with lymph node dissection. The final histopathological diagnosis was gastric schwannoma and tubular adenoma of the gallbladder. Gastric schwannoma accounts for only 0.2% of all gastric tumors, and tubular adenoma constitutes only 2.2% of gallbladder tumors. This report describes the diagnosis and treatment process for this combination of tumors, thus providing a reference for similar cases.

Laparoscopic-assisted endoscopic full-thickness resection of a large gastric schwannoma: A case report.

BACKGROUND: Schwannomas, also known as neurinomas, are benign tumors derived from Schwann cells. Gastrointestinal schwannomas are rare and are most frequently reported in the stomach. They are usually asymptomatic and are difficult to diagnose preoperatively; however, endoscopy and imaging modalities can provide beneficial preliminary diagnostic data. There are various surgical options for management. Here, we present a case of a large gastric schwannoma (GS) managed by combined laparoscopic and endoscopic surgery. CASE SUMMARY: A 28-year-old woman presented with a 2-mo history of epigastric discomfort and a feeling of abdominal fullness. On upper gastrointestinal endoscopy and endoscopic ultrasonography, a hypoechogenic submucosal mass was detected in the gastric antrum: It emerged from the muscularis propria and projected intraluminally. Computed tomography showed a nodular lesion (4 cm × 3.5 cm), which exhibited uniform enhancement, on the gastric antrum wall. Based on these findings, a preliminary diagnosis of gastrointestinal stromal tumor was established, with schwannoma as a differential. Considering the large tumor size, we planned to perform endoscopic resection and to convert to laparoscopic treatment, if necessary. Eventually, the patient underwent combined laparoscopic and gastroscopic surgery. Immunohistochemically, the resected specimen showed positivity for S-100 and negativity for desmin, DOG-1, α-smooth muscle actin, CD34, CD117, and p53. The Ki-67 index was 3%, and a final diagnosis of GS was established. CONCLUSION: Combined laparoscopic and endoscopic surgery is a minimally invasive and effective treatment option for large GSs.

Gastric Schwannoma as an Important and Infrequent Differential Diagnosis of Gastric Mesenchymal Tumours: A Case Report and Review of Literature.

The spectrum for gastrointestinal tract mesenchymal tumours includes leiomyomas, leiomyosarcomas, gastrointestinal stromal tumours (GISTs) and schwannomas. Schwannomas (also known as neuroma, neurilemmomas or neurinomas of Verocay) are well-known slow-growing, benign neoplasms that originate from nerve plexuses within a Schwann cell sheath. They can arise anywhere along the course of the peripheral nerve and are frequently reported around the head and neck, brachial plexus and along the gastrointestinal tract. Usually, these tumours are detected as solitary; however, they can occur at multiple sites around the body. Schwannomatosis (multiple schwannomas) is usually associated with neurofibromatosis type 2; the pathogenesis is triggered by mutations of the neurofibromatosis 2 tumour suppressor gene resulting in a loss of its function. Solitary gastric schwannomas are rare lesions that arise from the nerve plexus of the gastric wall. Frequently they are detected incidentally or may present with nonspecific abdominal pain or bleeding. This paper reports the case of a 79-year-old patient diagnosed with gastric schwannoma after presenting with abdominal pain. Gastric schwannomas should be taken into consideration while making a differential diagnosis of lesions that are gastric mesenchymal tumours, which span a broad spectrum. Gastric schwannomas are typically benign, considerably less common than gastric GISTs, and have an excellent prognosis following excision.

A radiologic diagnostic scoring model based on CT features for differentiating gastric schwannoma from gastric gastrointestinal stromal tumors.

We aimed to further explore the CT features of gastric schwannoma (GS), propose and validate a convenient diagnostic scoring system to distinguish GS from gastric gastrointestinal stromal tumors (GISTs) preoperatively. 170 patients with submucosal tumors pathologically confirmed (GS n=35; gastric GISTs n=135) from Hospital 1 were analyzed retrospectively as the training cohort, and 72 patients (GS=11; gastric GISTs=61) from Hospital 2 were enrolled as the validation cohort. We searched for significant CT imaging characteristics and constructed the scoring system via binary logistic regression and converted regression coefficients to weighted scores. The ROC curves, AUCs and calibration tests were carried out to evaluate the scoring models in both the training cohort and the validation cohort. For convenient assessment, the system was further divided into four score ranges and their diagnostic probability of GS was calculated respectively. Four CT imaging characteristics were ultimately enrolled in this scoring system, including transverse position (2 points), location (5 points), perilesional lymph nodes (6 points) and pattern of enhancement (2 points). The AUC of the scoring model in the training cohort were 0.873 (95% CI, 0.816-0.929) and the cutoff point was 6 points. In the validation cohort, the AUC was 0.898 (95% CI, 0.804-0.957) and the cutoff value was 5 points. Four score ranges were as follows: 0-3 points for very low probability of GS, 4-7 points for low probability; 8-9 points for middle probability; 10-15 points for very high probability. A convenient scoring model to preoperatively discriminate GS from gastric GISTs was finally proposed.