Endoscopic ultrasound features of gastric schwannomas with radiological correlation: A case series report

Differential diagnosis of submucosal gastric tumors: gastric schwannomas misdiagnosed as GISTs

Schwannomas commonly occur in the head and neck region but are rarely seen in the gastrointestinal tract; the stomach and small intestine are the most commonly involved sites. These tumors are usually misdiagnosed as gastrointestinal stromal tumors (GISTs) before histopathological confirmation due to radiological similarity. GI schwannomas show positivity for S100 protein and vimentin but are negative for CD 117 and CD 34, which helps in differentiating the tumor from GISTs. Case 1: a 70-year-old woman was referred to our hospital by complaints of abdominal pain and discomfort. Upper GI endoscopy demonstrated a protruding lesion at the lesser curvature of the gastric body, and fine-needle aspiration biopsy showed chronic inflammation without malignancy. Since the lesion was suspected to be GIST, this patient had surgery, and a gastric schwannoma was resected successfully. Case 2: a 66-year-old female with anemia and abdominal discomfort was found to have a submucosal elevated mass at the greater curvature of the antrum. Fine needle aspiration biopsy was suggestive of a spindle cell tumor resembling GIST. The patient underwent subtotal gastrectomy with Roux-en-Y reconstruction. Histopathology confirmed schwannoma. It is necessary to differentiate gastric schwannomas from other submucosal tumors of the stomach, especially GISTs. Surgical complete resection of schwannomas usually has a good prognosis with a low probability of recurrence. Though rare, gastric schwannomas should be included in the differential diagnosis of submucosal gastric tumors because the correct identification of this tumor type helps in proper management and evasion of unnecessary extensive surgery.

Laparoscopic resection for gastric schwannoma larger than 30 mm with long-term outcomes

BACKGROUND AND AIMS

Laparoscopic resection has been reported as effective and safe for gastric schwannoma (GS) in the form of case reports. However, study on laparoscopic surgery in patients with GS larger than 30 mm has been rarely reported. To this end, the present study aimed to evaluate the safety and efficacy of laparoscopic resection for the treatment of GS larger than 30 mm and its long-term outcomes.

METHODS

This is a retrospective case series study of patients with GS larger than 30 mm who underwent laparoscopic resection at our hospital between January 2014 and December 2020. Clinical pathology, surgical and follow-up data were collected and analyzed.

RESULTS

A total of 10 patients with a mean age of 51.6 years were included. Seven tumors were located in gastric body, 2 in antrum and 1 in fundus. Laparoscopic gastric wedge resection was performed in 7 patients, while laparoscopic gastric local resection was performed in 3 patients. All patients achieved complete resection. The mean operation time was 112.6 ± 34.3 min, and the mean postoperative hospital stay was 13.8 ± 5.1 days. Postoperative gastroplegia occurred in 2 patients and was treated with conservative therapy. No recurrence, metastasis or residue was found during the follow-up of mean 45.1 months.

CONCLUSIONS

Laparoscopic resection is a safe and effective method for treating GS larger than 30 mm with favorable long-term follow-up outcomes. Laparoscopic resection may be considered as the first-line treatment for GS larger than 30 mm.

Cytopathology of rare gastric mesenchymal neoplasms: A series of 25 cases and review of literature

BACKGROUND

Gastrointestinal stromal tumour (GIST) is the most common mesenchymal neoplasm arising in the stomach. However, a number of other rare mesenchymal neoplasms do occur at this anatomic site, which often presents a diagnostic challenge for cytopathologists on endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). Our study aims to selectively present the clinico-radiological and cytopathological characteristics of these rare "non-GIST" neoplasms, as well as their differential diagnoses.

MATERIAL AND METHODS

We performed a 20 year retrospective search in the cytopathology database of our two large medical institutions for non-GIST mesenchymal neoplasms arising in the stomach and diagnosed on EUS-FNA. Data regarding the patients' demographics and radiological findings were analysed. All available cytopathology specimens were reviewed. The cytomorphological characteristics and the accompanying immunohistochemical stains, when available, were subsequently analysed.

RESULTS

Twenty-five cases of gastric mesenchymal tumours were selectively included in the study after excluding all cases of GIST (n = 113) diagnosed on FNA. These cases included 10 leiomyomas (40%), eight schwannomas (32%), five glomus tumours (20%), one perivascular epithelioid cell neoplasm, and one desmoid tumour. The specimen cellularity was variable and ranged from hypocellular to highly cellular. Most smears were composed of spindle cells with a few showing epithelioid morphology. Cell blocks were available in 20 cases and a range of immunohistochemical ancillary studies were performed. DOG-1, c-KIT, smooth muscle actin (SMA), and S100-protein were the most common immunomarkers done.

CONCLUSION

Our study highlights important cytomorphological characteristics of rare mesenchymal neoplasms arising in the stomach. In the appropriate clinical setting and with the help of immunohistochemistry, an accurate diagnosis of these neoplasms can be achieved.

Clinicopathological characteristics of gastrointestinal schwannomas: A retrospective analysis of 78 cases

INTRODUCTION

Schwannomas are tumors arising from Schwan cells of the neural sheath, which rarely occur in the gastrointestinal tract. The aim of the present study was to analyze the clinicopathological features and treatment outcomes of gastrointestinal schwannomas (GISs).

METHODS

Patients who were diagnosed with GISs in our hospital from January 2010 to December 2021 were selected. Data about demographic characteristics, clinical symptoms, treatment methods and outcomes, pathological results, and follow-up results were retrospectively collected and analyzed.

RESULTS

A total of 78 patients with 79 GISs were included, the female-to-male ratio was 55:23, and the average age was 52.12 ± 12.26 years. One-third (26/78) of the patients were asymptomatic. A total of 79 GISs were removed, and the average size was 3.63 ± 2.03 cm (range, 0.3-10 cm). As for tumor location, 54 GISs were located in the stomach, 14 in the esophagus, 2 in the duodenum, 6 in the colorectum (4 in the colon and 2 in the rectum), and the other 3 in the small intestine. A total of 23 and 55 patients underwent endoscopic and surgical resections, respectively. Compared with surgical resection, endoscopic resection is associated with a smaller diameter, lower cost, and shorter hospital stay. Pathological results revealed that S100 was positive in all the GISs. No recurrence was noticed during a median follow-up of 45 months (range, 6-148 months).

CONCLUSION

GISs are rare gastrointestinal tumors with favorable prognoses, which are most commonly seen in the stomach and diagnosed by pathological findings with immunohistochemical staining. Surgical resection remains the standard method for removing GISs, while endoscopic resection may serve as an alternative method for selected patients with GISs and may be attempted in GISs with a diameter of <3 cm and no signs of malignancy.

Schwannoma of the Appendix Orifice

Schwannomas are rare mesenchymal tumors. They are usually diagnosed incidentally during endoscopic or diagnostic imaging for another reason. Malignant transformation is rare. In this case report, we present an incidental schwannoma protruding through the appendiceal orifice diagnosed during endoscopy. A healthy 56-year-old female underwent a surveillance colonoscopy for family history of colorectal cancer. A prominent and edematous appendiceal orifice was noted, and the area was aggressively biopsied. Histopathological assessment revealed a benign schwannoma. Computerized topography was unremarkable. Subsequently, the patient underwent a right hemicolectomy. Patient is scheduled to undergo routine surveillance in three years. Grossly, schwannomas are white, encapsulated, and well-circumscribed lesions that stain strongly positive for S100, GFAP, and CD57. Histologically, schwannomas demonstrate spindle cell proliferation. Several imaging modalities have been utilized in the diagnosis and management of mesenchymal neoplasms. Despite the benign nature of the diagnosis, complete surgical resection with clear margins remains the gold standard management strategy. Our case highlights the presence of a relatively uncommon tumor in an unusual anatomical location.

Gastric schwannoma treated by endoscopic full-thickness resection and endoscopic purse-string suture: A case report

BACKGROUND

Schwannomas, also known as neurinomas, are tumors that derive from Schwann cells. Gastrointestinal schwannomas are extremely rare, but the stomach is the most common site. Gastric schwannomas are usually asymptomatic. Endoscopy and imaging modalities might offer useful preliminary diagnostic information. However, to diagnose schwannoma, the immunohistochemical positivity for S-100 protein is essential, whereas CD117, CD34, SMA, desmin, and DOG-1 are negative.

CASE SUMMARY

A 45-year-old female was found to have a gastric mass during a medical examination, which was diagnosed as a gastric schwannoma. We performed endoscopic full-thickness resection and endoscopic purse-string suture. Pathology and immunohistochemical staining confirmed the diagnosis of gastric schwannoma through the positivity of S-100 protein. Furthermore, to exclude the misdiagnosis of gastrointestinal stromal tumor, we performed a mutational detection of the c-Kit and PDGFRA genes. Postoperative follow-up revealed that the patient recovered well.

CONCLUSION

Immunohistochemical staining is essential for the diagnosis of schwannoma. Endoscopic full-thickness resection is an effective treatment method for gastric schwannoma.

What About Gastric Schwannoma? A Review Article

PURPOSE

Gastric schwannomas (GSs) are rare mesenchymal neoplasms of the gastrointestinal tract. Diagnosis is often achieved postoperatively, based on pathology reports of retrieved specimens. The aim of the present study is to follow up all patients with gastric schwannoma (Gs) undergoing endoscopic, partial, or more extended surgery and to evaluate the appearance of local or distant recurrence.

METHODS

A PubMed, Cochrane, and Embase systematic review of the literature has been performed. Original papers, review articles, and case reports published between 1988 and 2019 were considered eligible. All the studies who met the inclusion criteria were analyzed. Statistical analysis of data has been performed using GraphPad Prism 7 software.

RESULTS

Three hundred twenty-eight articles were found, and a total of 102 were included and analyzed in depth. Fifty-three papers reported the follow-up information, ranging from 1 to 417 months across different studies. Among them, 31 patients underwent endoscopic removal of the gastric lesions; 140 patients underwent local surgery, including wedge resection or partial gastrectomy; and 148 patients underwent subtotal or total gastrectomy. The median follow-up was of 27-38-33 months, respectively. No recurrence or distant metastasis was detected in the endoscopy group. Among local surgery group, liver metastasis was reported in one case; in extended surgery group, one patient died for multiple liver metastases.

CONCLUSIONS

Local or more extended surgery involved a larger cohort of patients and reported satisfactory long-term results compared with endoscopy group. Surgery in absence of a definite preoperative diagnosis is considered the gold standard treatment for resectable Gs.

Endoscopic resection of benign esophageal schwannoma: Three case reports and review of literature

BACKGROUND

Esophageal schwannomas are uncommon esophageal submucosal benign tumors and are usually treated with surgery.

CASE SUMMARY

Here, we report three cases of middle/lower thoracic esophageal schwannoma treated successfully with endoscopic resection. These lesions were misdiagnosed as leiomyoma on preoperative imaging. During the endoscopic resection of such tumors, there is a risk of esophageal perforation due to their deep location. If possible, submucosal tunneling endoscopic resection should be used.

CONCLUSION

For larger schwannomas, endoscopy combined with thoracoscopy can be considered for en bloc resection. We performed a mini literature review in order to present the current status of diagnosis and treatment for esophageal schwannoma.

Clinical Characteristics and Surgical Management of Gastrointestinal Schwannomas

OBJECTIVES

Schwannomas are tumors arising from Schwan cells of the neural sheath. Gastrointestinal schwannomas (GS) are rare and easily confused with a heterogeneous group of neuroectodermal or mesenchymal neoplasms. The aim of the present study is to analyze the clinicopathological features, surgical management methods, and long-term prognoses of GS patients.

METHODS

Between August 2004 and July 2019, 51 patients with GS were treated at the Peking Union Medical College Hospital. The medical records were reviewed retrospectively. A database containing demographic characteristics, clinical symptoms, imaging tests, operation details, pathological results, and prognoses was constructed and analyzed.

RESULTS

GS accounted for 2.0% of all schwannomas. The cohort comprised 19 men (37.3%) and 32 women (62.7%). The mean age was 55.7 ± 11.4 years. The most common symptom was abdominal pain (29.4%). Twenty-seven patients (52.9%) were asymptomatic and diagnosed incidentally. The most common tumor location of GS was the stomach (90.2%). S-100 had the highest positive rate (100%) in immunohistochemical staining. Forty-six patients (90.2%) were followed-up at a mean period of 49.5 ± 41.4 months. Forty-four patients (95.7%) survived without tumor, 1 patient survived with tumor, and 1 patient died. The 5-year cumulative overall survival rate and cumulative disease-free survival rate were 97.5% and 95.2%, respectively.

CONCLUSION

GS are rare gastrointestinal tumors with favorable prognoses after surgical resection. Stomach is the most common site. Definitive diagnosis is determined by postoperative pathology. S-100 expression has diagnostic significance.

Endoscopic ultrasound FNA: An illustrated review of spindle cell neoplasms of the upper gastrointestinal tract including a novel case of gastric plexiform fibromyxoma

Plexiform fibromyxoma (PF) is a recently-described and rare mesenchymal neoplasm of the gastric wall. A few small case series reports of this spindle cell entity exist in the surgical pathology literature, but to our knowledge no prior endoscopic ultrasound guided fine needle aspiration cytology examples have been reported. In clinical practice, mural gastrointestinal (GI) lesions are often initially evaluated by endoscopic ultrasound guided (EUS) fine needle aspiration (FNA). In addition, newer EUS fine needle biopsy techniques also allow for reliable retrieval of core tissue samples with intact cellular architecture, making EUS histopathologic analyses possible. We report a combined EUS FNA and core biopsy case of PF and correlate the findings with imaging results. The cytomorphology of PF is described and illustrated, and important entities in the differential diagnosis of upper GI spindle cell lesions (including GI stromal tumor, leiomyoma, schwannoma, carcinoid tumor, desmoid-type fibromatosis, and inflammatory fibroid polyp) are reviewed. Illustrated examples of relevant cytomorphologic, cell block histomorphologic and immunohistochemical characteristics are emphasized.

Gastric Schwannoma: A Tumor Must Be Included in Differential Diagnoses of Gastric Submucosal Tumors

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. Due to its rarity, GS is not widely recognized by clinicians, and the precise differential diagnosis between GS and other gastric submucosal tumors remains difficult preoperatively. The present study reports a case of GS misdiagnosed as gastrointestinal stromal tumor and reviews the clinical, imaging, and pathological features, treatment, and follow-up of 221 patients with GS previously reported in the English literature. Although GS is rare, the case reported in the current study highlights the importance of including GS in differential diagnoses of gastric submucosal tumors. Furthermore, the findings of the review suggest that although many cases are asymptomatic, the most common symptoms are abdominal pain or discomfort, not gastrointestinal bleeding, and malignant GSs present with clinical symptoms more commonly. Although large-sample multicenter studies on the efficacy, safety, and oncological outcomes of minimally invasive techniques are required, the findings presented herein may be helpful for clinicians when diagnosing or treating GS.

Endoscopic ultrasonographic characteristics of gastric schwannoma distinguished from gastrointestinal stromal tumor

BACKGROUND/AIMS

Gastric schwannoma (GS), a rare neurogenic mesenchymal tumor, is usually benign, slow-growing, and asymptomatic. However, GS is often misdiagnosed as gastrointestinal stromal tumors (GIST) on endoscopic and radiological examinations. The purpose of this study was to evaluate EUS characteristics of GS distinguished from GIST.

METHODS

A total of 119 gastric subepithelial lesions, including 31 GSs and 88 GISTs, who were histologically identified and underwent EUS, were enrolled in this study. We evaluated the EUS characteristics, including location, size, gross morphology, mucosal lesion, layer of origin, border, echogenic pattern, marginal halo, and presence of an internal echoic lesion by retrospective review of the medical records.

RESULTS

GS patients comprised nine males and 22 females, indicating female predominance. In the gross morphology according to Yamada's classification, type I was predominant in GS and type III was predominant in GIST. In location, GSs were predominantly located in the gastric body and GISTs were predominantly located in the cardia or fundus. The frequency of 4th layer origin and isoechogenicity as compared to the echogenicity of proper muscle layer was significantly more common in GS than GIST. Although not statistically significant, marginal halo was more frequent in GS than GIST. The presence of an internal echoic lesion was significantly more common in GIST than GS.

CONCLUSIONS

The EUS characteristics, including tumor location, gross morphology, layer of origin, echogenicity in comparison with the normal muscle layer, and presence of an internal echoic lesion may be useful in distinguishing between GS and GIST.

Endosonographic Features of Gastric Schwannoma: A Single Center Experience

BACKGROUND/AIMS

Gastric schwannomas are rare benign mesenchymal tumors that are difficult to differentiate from other mesenchymal tumors with malignant potential, such as gastrointestinal stromal tumors. This study aimed to evaluate the characteristic findings of gastric schwannomas via endoscopic ultrasonography (EUS).

METHODS

We retrospectively reviewed the EUS findings of 27 gastric schwannoma cases that underwent surgical excision at Pusan National University Hospital during 2007 to 2014.

RESULTS

Gastric schwannomas were mainly located in the middle third of the stomach with a mean tumor size of 32 mm. All lesions exhibited hypoechoic echogenicity, and 24 lesions (88.9%) exhibited heterogeneous echogenicity. Seventeen lesions (63.0%) exhibited decreased echogenicity compared to the normal proper muscle layer. Distinct borders were observed in 24 lesions (88.9%), lobulated margins were observed in six lesions (22.2%), and marginal haloes were observed in 24 lesions (88.9%). Hyperechogenic spots were observed in 21 lesions (77.8%), calcifications were observed in one lesion (3.7%), and cystic changes were observed in two lesions (7.4%).

CONCLUSIONS

During EUS, gastric schwannomas appear as heterogeneously hypoechoic lesions with decreased echogenicity compared to the normal proper muscle layer. These features may be helpful for differentiating gastric schwannomas from other mesenchymal tumors.

Endoscopic Ultrasonography in the Diagnosis of Gastric Subepithelial Lesions

Subepithelial lesions occasionally found in the stomach of patients undergoing endoscopy may be either benign lesions or tumors with malignant potential. They may also appear due to extrinsic compression. Discrimination of gastric subepithelial lesions begins with meticulous endoscopic examination for size, shape, color, mobility, consistency, and appearance of the overlying mucosa. Accurate diagnosis can be achieved with endoscopic ultrasonography, which provides useful information on the exact size, layer-of-origin, and characteristic morphologic features to support a definitive diagnosis. Endoscopic ultrasonography also aids in the prediction of malignant potential, especially in gastrointestinal stromal tumors. Features of subepithelial lesions identified on endoscopic ultrasonography can be used to determine whether further diagnostic procedures such as endoscopic resection, fine needle aspiration, or core biopsy are required. Endoscopic ultrasonography is a valuable tool for diagnosis and clinical decision making during follow-up of gastric subepithelial lesions.

Clinicopathologic Features of Gastric Schwannoma: 8-Year Experience at a Single Institution in China

To explore the clinicopathologic characteristics, diagnosis, treatment, and prognosis of gastric schwannoma in the imatinib era.The clinicopathologic characteristics and postoperative outcomes of patients diagnosed with gastric schwannoma at our institution between January 2007 and February 2015 were retrospectively collected and analyzed.The main patient complaint was epigastric pain or discomfort. Tumor sizes ranged from 15 to 80 mm (mean, 57.1 mm). In 17 patients, the tumors were located in the body of the stomach. A total of 20 patients were preoperatively misdiagnosed with a gastrointestinal stromal tumor. The rate of correct preoperative diagnosis was only 3.3%. All patients underwent surgical resection and showed strong S-100 protein positivity. Laparoscopic surgery for gastric schwannoma was associated with less blood loss and a shorter postoperative hospital stay than open surgery (P < 0.01). Total 28 patients were disease free without recurrence or metastasis at a median follow-up time of 50 months.Gastric schwannoma is often preoperatively misdiagnosed as gastric gastrointestinal stromal tumor. Laparoscopic resection of gastric schwannoma is considered safe and effective, and it may be the preferred surgery for most small- and moderate-sized tumors. The long-term outcome is excellent, as this type of neoplasm is uniformly benign.

Diagnostic and therapeutic value of endoscopic ultrasonography in gastric schwannoma

AIM: To assess the diagnostic and therapeutic value of endoscopic ultrasonography in gastric schwannoma.

METHODS: Endoscopic ultrasonography features of 12 cases of pathologically and immunohistochemically confirmed gastric schwannoma were retrospectively analyzed.

RESULTS: The tumor was located in the gastric body in 6 patients, in the gastric antrum in 5 patients, and in the cardia in 1 patient. On endoscopic ultrasound they were observed as hypoechoic tumors arising most commonly from the proper muscle layer, accompanied by hypoechoic halo and rich blood supply. In one patient in whom the tumor was located in the pylorus, endoscopic ultrasound showed mucosal break, but slight hyperecho was seen in the muscular layer. Ten patients received endoscopic treatment, of whom 6 were treated by endoscopic submucosal excavation, 3 by endoscopic full-thickness resection, and 1 by submucosal tunelling endoscopic resection. No bleeding, inflammation or infection occurred. The average follow-up time was 10.0 mo ± 1.9 mo. No recurrence or metastasis was found during follow-up.

CONCLUSION: Endoscopic ultrasonography is safe and effective in the diagnosis and treatment of gastric schwannoma.

Endoscopic interventional treatment for gastric schwannoma: a single-center experience

BACKGROUND AND AIMS

Endoscopic Interventional Treatment is of little trauma and less complications in the treatment of gastric schwannoma and leads to faster recovery and fewer days of hospitalization. This study was aimed to investigate the safety and efficacy of endoscopic interventional therapy for gastric schwannoma, including endoscopic submucosal excavation, non-laparoscopic-assisted endoscopic full-thickness resection, endoscopic tunneling submucosal resection, and so on.

METHODS

Six patients of gastric schwannoma diagnosed by pathology examination were retrospectively analyzed ranging from Oct 2011 to Feb 2014 at Shandong Provincial Hospital affiliated to Shandong University. Five of the six patients accepted endoscopic interventional therapy.

RESULTS

Among the five patients, there were four males and one female, aged from 48 to 65 years old (the average age was 58 ± 6.4). The lesions located at the fundus, the fundus-cardia, gastric body or gastric antrum, respectively, with the diameters ranged from 8 to 25 millimeter (the average was 17.1 ± 7.8 mm). All the patients were performed endoscopic interventional therapy successfully. Among five patients, one patient was treated by endoscopic tunneling submucosal resection, two by endoscopic submucosal excavation, and the other two were given endoscopic full-thickness resection. Operation duration was about 43 to 83 minutes (the average was 57.6 ± 16.1 minutes). The mass were completely removed, with limited bleeding. During the operation, perforation and pneumoperitoneum occurred in two patients, who finally recovered by endoscopic and conservative treatment. No bleeding, inflammation or infection occurred in these patients. The average follow-up time was (7.4 ± 4.4) months. Neither recurrence nor metastasis was found during follow-up.

CONCLUSION

Endoscopic interventional therapy is a safe and effective treatment for gastric schwannoma.