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-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: 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: 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.

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.

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: 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.

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.

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.

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 misdiagnosed as gastrointestinal stromal tumor by ultrasonography before surgery: A case report.

BACKGROUND: Gastric origin tumors were diagnosed and evaluated preoperatively by gastroscopy, endoscopic ultrasonography, computed tomography (CT) or magnetic resonance imaging. Currently, transabdominal high-resolution ultrasound combined with gastrointestinal contrast agent can be used to diagnose stomach tumors effectively and without invasive procedures or radiation. However, although an appreciable number of cases of gastric schwannoma (GS) have been reported since the first description of such in 1988, the ongoing lack of a comprehensive list of ultrasonic characteristics has limited the accuracy of preoperative ultrasound diagnosis. CASE SUMMARY: A 64-year-old female patient presented to our hospital with dizziness and head discomfort. During an abdominal ultrasound, a hypoechoic gastric mass was found, having clear and regular boundaries and no observable blood flow. Based on these characteristics, a gastrointestinal stromal tumor was suspected. Results from an endoscopic ultrasound biopsy and accompanying immunohistochemical analysis, coupled with abdominal CT findings indicating lymph node enlargement around the stomach, led to diagnosis of GS but did not exclude malignancy. After surgical resection of the tumor, the final diagnosis of GS without lymph node metastasis was made. No recurrence has occurred in the 6 years of follow-up. CONCLUSION: A clearly defined ultrasonic characteristic profile of GS is important to improve diagnostic accuracy.

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.