The value of enhanced computed tomography-based nomograph model in the differential diagnosis of gastric schwannoma and gastric stromal tumor / 中华消化杂志

Objective:To construct enhanced computed tomography (CT)-based nomograph model, to assist physicians in differentiating gastric schwannoma from gastric stromal tumor.Methods:From January 1, 2012 to January 1, 2022, at the Second Affiliated Hospital of Zhejiang University School of Medicine and Ningbo Hwamei Hospital, University of Chinese Academy of Sciences, 57 patients with gastric schwannoma and 275 patients with gastric stromal tumor confirmed by surgical pathology were retrospectively collected, among whom 39 patients with gastric schwannoma and 201 patients with gastric stromal tumor were enrolled in the training set, and the other 18 patients with gastric schwannoma and 74 patients with gastric stromal tumor were enrolled in the validation set. The contrast-enhanced CT imaging features (tumor size index, arterial phase CT value, venous phase CT value, necrosis, calcification, integrity of mucosal surface, and uniform enhancement, etc.) and clinical data (history of gastritis, carbohydrate antigen 19-9 (CA19-9), carcinoembryonic antigen, and monocyte to lymphocyte ratio (MLR), etc.) were collected. The least absolute shrinkage and selection operator (LASSO) regression analysis was used to screen the independent predictive factors of imaging features in the differential diagnosis of gastric schwannoma and gastric stromal tumor, and a nomograph model was constracted. Logistic regression analysis was used to analyze and screen the independent predictive factors of clinical indicators to distinguish gastric schwannoma from gastric stromal tumor, and a clinical control model was established. The receiver operating characteristic curve(ROC) was used to analyze the area under the curve (AUC) of the nomograph model in the training set and the verification set, and concordance index (CI) and decision curve analysis (DCA) were used to evaluate the predictive efficiency and clinical application value of the nomograph model. DeLong test was used for statistical analysis.Results:The results of LASSO regression analysis showed that tumor size index, arterial phase CT value, venous phase CT value, necrosis, calcification, integrity of mucosal surface, and uniform enhancement were independent predictive factors of imaging features in the differential diagnosis of gastric schwannoma and gastric stromal tumor(all P<0.05). The results of logistic regression analysis indicated that the history of gastritis ( OR=0.280, 95% confidence interval 0.138 to 0.566), CA19-9 ( OR=0.940, 95% confidence interval 0.890 to 0.993), carcinoembryonic antigen ( OR=0.794, 95% confidence interval 0.661 to 0.952), and MLR ( OR=0.087, 95% confidence interval 0.009 to 0.860) were independent predictive factors of clinical indicators in the differential diagnosis of gastric schwannoma and gastric stromal tumor ( P<0.001, =0.028, 0.013 and 0.037). The AUCs of the nomograph model in the training and validation set were 0.881 and 0.850, respectively, and the AUCs of the clinical control model in the training and validation set were 0.814 and 0.772, respectively, and the differences were statistically significant ( Z=2.57 and 1.96, P=0.005 and 0.030). The average CI of the nomograph model was 0.885. The results of DCA analysis showed that the overall benefit of the nomograph model was higher than that of the clinical control model. Conclusion:The enhanced CT-based nomograph model can effectively distinguish gastric schwannoma from gastric stromal tumor, and can help physicians to make precise clinical decisions.

Gastric Schwannoma mimicking gastrointestinal stromal tumor: a rare case with review of literature

Gastric schwannoma (GS) is a rare neoplasm of the stomach. It accounts for 0.2% of all gastric tumors and is mostly benign, slow-growing, and asymptomatic. Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors and up to 60-70% of GIST occur in the stomach. Schwannoma and GIST have similar radiological and endoscopic features making it extremely difficult to differentiate them preoperatively. Differential diagnosis of these two submucosal tumors is important because of the malignant potential of GIST and the relatively benign course of gastric schwannomas. This case stresses on the importance of including gastric schwannomas in the differential diagnosis of a submucosal gastric mass as it has the ability to mimic a gastrointestinal stromal tumor, which is a leading differential diagnosis because of its common occurrence at this site.

MSCT findings of gastric schwannomas / 实用放射学杂志

Objective To explore the MSCT characteristics of gastric schwannoma (GS).Methods 1 6 patients with pathologically verified GS were included in our study.The MSCT images were analysed retrospectively.Results 1 6 participants were determined with solitary nodule,which located in gastric antrum,body and fundus,respectively with 5 cases,10 cases and 1 case.13 of them showed morphologically as round or ovoid shape,while 3 of them grew irregularly lobulated lesion.For their growth pattern,1 3 tumors presented as bilateral growth,1 lesion appeared intra-cavitary growth,1 grew outside the cavity fields.However,1 case was hard to confirm the growth pattern due to the gastroduodenal intussusception.14 tumors appeared uniform density,1 showed a little necrosis and 1 had dotted calcification,all the lesions were emerged as progressive enhancement with inhomogeneous feature.Conclusion GS mostly located in gastric body or antrum,with round or ovoid appearence,well-defined border,and bilateral growth pattern,necro-sis and calcification are rare,enhanced progressively with homogeneous feature,with no surrounding invasion and metastasis.

4 cases of gastric schwannoma misdiagnosed as gastric stromal tumors by endoscopic ultrasonography and literature review / 中国内镜杂志

Objective To improve detectable rate of gastric schwannoma by endoscopic ultrasonography (EUS). Method Clinical data and endoscopic ultrasonography (EUS) imaging features of 4 cases were retrospectively ana-lyzed which diagnosed as gastric schwannoma pathologically and immunohistochemically while diagnosed as gastric stromal tumor by EUS from May 2008 to June 2015 and reviewed the literature. Results 4 cases of gastric schwan-nomas are female and benign, all 4 lesions are solitary, 3 in gastric body, and 1 in fundus by endoscopic. By EUS, all lesions are originated from muscularis propria, hypoechoic change, even echoes and clear board without calcifica-tion or cystic changes. 2 cases have halo artifacts around the lesion. Literature review found that gastric schwannoma tended to occur in female, halo artifacts could be the feature of gastric schwannoma, calcification or cystic changes were rare in gastric schwannoma which were common in gastric stromal tumors. Conclusion It was difficult to distin-guish gastric schwannoma and gastric stromal tumors that originated from muscularis propria by EUS. For female patients with lesions originated from muscularis propria, originated from muscularis propria and occurred in gastric body, it was necessary to observe lesions whether there was being calcification or cystic and halo artifacts. Integrated all these performance, we should be in consideration of gastric stromal tumors, meanwhile, excluding the possibility of gastric schwannoma.

Gastric Schwannoma Diagnosed by Endoscopic Ultrasonography-Guided Trucut Biopsy

Schwannomas of the gastrointestinal (GI) tract are rare subepithelial tumors comprising approximately 3.3% to 12.8% of all mesenchymal tumors of the GI tract. On endoscopic ultrasound (EUS) they are seen as hypoechoic tumors arising most commonly from the 4th proper muscle layer. Although EUS helps to distinguish tumor characteristics, tissue sampling is required for differentiation with other more common tumors such as GI stromal tumors. Both EUS-guided fine needle aspiration and EUS-guided trucut biopsy (EUS-TCB) can be used for tissue sampling. However, only EUS-TCB allows core biopsy and a high yield of immunohistochemical staining. We report a case of a gastric schwannoma diagnosed by EUS-TCB.

Huge Gastric Schwannoma Characterized by a Gastric Ulcer During Endoscopy / 대한소화기내시경학회지

Gastric schwannomas are very rare mesenchymal tumors that can occur throughout the gastrointestinal tract, but are most commonly found in the stomach. The majority of patients have no symptoms, while others may complain of epigastric pain or upper gastrointestinal ulcer bleeding. Endoscopic examination of a gastric schwannoma commonly reveals a protrusive mass, but, as in this case, many types of ulceration can be observed with central necrosis. We report on a 62-year-old woman with endoscopic findings of 1 cm sized necrotizing ulceration and an 11 cm sized submucosal mass on radiological examinations. The patient underwent a wedge-shaped resection of the stomach and segmental resection of the transverse colon. Both histological and immunohistochemical staining revealed a gastric schwannoma.

Gastric Schwannoma Treated by Laparoscopic Surgery

Gastric schwannoma is a very rare gastrointestinal mesenchymal tumor. Schwannoma in the gastrointestinal tract is usually not symptomatic, and preoperative abdominal CT or endoscopic evaluation cannot distinguish it from gastrointestinal stromal tumor. Surgical resection of this tumor is adequate to achieve a good prognosis. We performed laparoscopic gastric wedge resection in two patients who had the preoperative diagnosis of gastric gastrointestinal stromal tumor. In both cases, the postoperative immunohistochemistry staining was positive for S-100 protein and it was negative for CD34, which is consistent with gastric schwannoma. We report here on two cases of gastric schwannoma along with a review of the literatures.

Two Cases of Gastric Schwannomas: with Ulcer and without Ulcer / 대한소화기내시경학회지

A Schwannoma is a benign tumor that originates from Schwann cells in the gastric wall. The tumor is mainly asymptomatic but sometimes can cause bleeding of the upper GI tract. We encountered a Schwannoma that was identified by gastroscopy as a submucosal mass that might be malignant. Therefore, surgery was considered as the primary treatment. The Schwannoma was confirmed retrospectively by a pathologic examination after excising the mass. This case report is a comparative study into Schwanoma with and without central ulceration. Pathologically, atypia of the cell was discovered in the case accompanied by an ulcer, which is a secondary phenomenon caused by the degeneration that does not indicate the malignancy.