Gastrointestinal schwannomas: a rare but important differential diagnosis of mesenchymal tumors of gastrointestinal tract

Incidental Finding of an Asymptomatic Jejunal Schwannoma: A Rare Case Report and Review of Literature

BACKGROUND Schwannomas are tumors that arise from Schwann cells that surround and support nerve cells. Most common sites for presentations are head, neck, and extremities. Schwannomas of gastrointestinal tract are rare, slow-growing tumors, usually benign, arising from gastrointestinal tract's neural plexus. They are histologically distinguishable from conventional schwannomas that arise in soft tissue or the central nervous system. Preoperative diagnosis of gastrointestinal schwannoma is challenging, requiring immunohistological confirmation of the nature of the tumor. Here, we report a case of 57-year-old woman with an incidental finding of an asymptomatic submucosal jejunal schwannoma. CASE REPORT A 57-year-old woman with a medical history of hematological disorder underwent a contrast abdominal computed tomography as part of medical follow-up. The imaging revealed the presence of a jejunal mass. The patient underwent laparoscopic surgical resection of the lesion, followed by side-to-side jejuno-jejunal anastomosis with 4-cm clear surgical margins. The final pathologic study revealed the presence of jejunal schwannoma, as tested positive for S-100 protein. The patient was discharged home on the fourth postoperative day, having an uneventful recovery. CONCLUSIONS Jejunal schwannoma are usually benign and asymptomatic, and they are often discovered incidentally during diagnostic tests for other conditions; therefore, it should be included in the differential diagnosis of gastrointestinal tumors. Surgical treatment appears to be necessary to achieve a definitive diagnosis through a biopsy of the tumor tissue. Benign jejunal schwannomas have a good prognosis.

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.

Ileal Schwannoma: A Rare Cause of Pelvic Mass

The incidence of small bowel schwannomas is extremely low. In the current literature, we found just a few reported small intestine schwannomas that were located in the duodenum, jejunum, or ileum. This study reports a surprising finding of a relatively large size ileal schwannoma in a patient whose preoperative magnetic resonance imaging described a tumour in the lesser pelvis probably derived from the right adnexa. Pfannenstiel incision was made by the gynaecology team, which found a large mass lesion arising from the small intestine and occupying nearly the entire lesser pelvis. The general surgeon was invited, and pathology was successfully managed by segmental resection of the small bowel with primary end-to-end anastomosis. The histopathology study reported a submucosal tumour composed of S-100 protein-positive spindle cells, and the diagnosis of ileal schwannoma was made. The possibility of intestinal neoplasms, including schwannomas, might be contemplated in the differential diagnosis of any pelvic mass lesions. A detailed histology study and immunohistochemical stain are required for the final diagnosis of intestinal schwannomas and to rule out malignant changes, which are extremely important for the further management of patients. To the best knowledge, our case is one of the biggest intestinal schwannomas reported in the current literature.

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.

Schwannoma of the Sigmoid Colon: A Rare Case

Schwannoma is a type of peripheral nerve sheath tumor that is often found in the head and neck. Schwannomas in the digestive system, particularly the colon and rectum, are exceptionally rare, and they are mostly non-malignant and asymptomatic although sometimes patients can present with symptoms similar to those observed in patients with other gastrointestinal tumors like abdominal pain, fullness, nausea, vomiting, and change in bowel habits. For diagnosis and treatment, surgical resection along with biopsy is the gold standard. In this paper, we describe a rare case of sigmoid schwannoma that was successfully treated in our department by surgical resection.

Computed tomographic imaging features to differentiate gastric schwannomas from gastrointestinal stromal tumours: a matched case-control study

To investigate clinical data and computed tomographic (CT) imaging features in differentiating gastric schwannomas (GSs) from gastric stromal tumours (GISTs) in matched patients, 31 patients with GSs were matched with 62 patients with GISTs (1:2) in sex, age, and tumour site. The clinical and imaging data were analysed. A significant (P < 0.05) difference was found in the tumour margin, enhancement pattern, growth pattern, and LD values between the 31 patients with GSs and 62 matched patients with GISTs. The GS lesions were mostly (93.5%) well defined while only 61.3% GIST lesions were well defined.The GS lesions were significantly (P = 0.036) smaller than the GIST lesions, with the LD ranging 1.5-7.4 (mean 3.67 cm) cm for the GSs and 1.0-15.30 (mean 5.09) cm for GIST lesions. The GS lesions were more significantly (P = 0.001) homogeneously enhanced (83.9% vs. 41.9%) than the GIST lesions. The GS lesions were mainly of the mixed growth pattern both within and outside the gastric wall (74.2% vs. 22.6%, P < 0.05) compared with that of GISTs. No metastasis or invasion of adjacent organs was present in any of the GS lesions, however, 1.6% of GISTs experienced metastasis and 3.2% of GISTs presented with invasion of adjacent organs. Heterogeneous enhancement and mixed growth pattern were two significant (P < 0.05) independent factors for distinguishing GS from GIST lesions. In conclusion: GS and GIST lesions may have significantly different features for differentiation in lesion margin, heterogeneous enhancement, mixed growth pattern, and longest lesion diameter, especially heterogeneous enhancement and mixed growth pattern.

Value of enhanced computed tomography in differentiating small mesenchymal tumours of the gastrointestinal from smooth muscle tumours

BACKGROUND

Computed tomography (CT) technology has been gradually used in the differentiation of small mesenchymal tumors of the stomach and intestines from smooth muscle tumours.

AIM

To explore the value of enhanced CT in the differentiation of small mesenchymal tumors of the stomach and intestines from smooth muscle tumours.

METHODS

Clinical data of patients with gastric mesenchymal or gastric smooth muscle tumours who were treated in our hospital from May 2018 to April 2023 were retrospectively analysed. Patients were divided into the gastric mesenchymal tumor group and the gastric smooth muscle tumor group respectively (n = 50 cases per group). Clinical data of 50 healthy volunteers who received physical examinations in our hospital during the same period were selected and included in the control group. Serum levels of carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), carbohydrate antigen 19-9 (CA19-9), CA-125 and cytokeratin 19 fragment antigen 21-1 were compared among the three groups. The value of CEA and CA19-9 in the identification of gastric mesenchymal tumours was analysed using the receiver operating characteristic (ROC) curve. The Kappa statistic was used to analyse the consistency of the combined CEA and CA19-9 test in identifying gastric mesenchymal tumours.

RESULTS

CEA levels varied among the three groups in the following order: The gastric mesenchymal tumour group > the control group > the gastric smooth muscle tumour group. CA19-9 levels varied among the three groups in the following order: The gastric mesenchymal group > the gastric smooth muscle group > the control group, the difference was statistically significant (P < 0.05). ROC analysis showed that the area under the curve of CEA and CA19-9 was 0. 879 and 0. 782, respectively.

CONCLUSION

Enhanced CT has shown value in differentiating small mesenchymal tumors of the stomach and intestines from smooth muscle tumors.

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.

Schwannoma of the colon: a rare submucosal neoplasm

Schwannomas are nerve sheath tumours that can be found throughout the body along peripheral nerves. Primary schwannomas of the colon are very rare. They are usually benign and their surgical resection is considered curative. They are, however, difficult to diagnose preoperatively and therefore tend to be overtreated with major colorectal surgery.

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.

GIST is not all that it seems

We present a 41-year-old female who was admitted to our hospital with a history of 2-month epigastric pain and vomiting. Physical examination was normal. Upper gastrointestinal endoscopy showed a sessile submucosal tumor with central ulceration in the gastric body-antrum. Biopsies revealed a gastric mucosa without changes. Nevertheless, endoscopic ultrasound-guided biopsies showed interlacing bundles of spindle cells. The immunohistochemical study was negative for CD117 and smooth muscle actin and positive for S100 protein. A CT scan identified a heterogeneous mass in the stomach wall.

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.

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 case of intestinal schwannoma initially suspected by transvaginal ultrasound

Schwannomas are peripheral nerve sheath tumors. Due to their low incidence, few cases of colorectal schwannomas have been published, which increases the diagnostic challenge. The aim of this case report is to discuss the role of transvaginal ultrasound in different areas than the gynecological disorders, when on hands of properly trained professionals that perform systematized procedures. A 56-year-old woman consulted for postmenopausal genital bleeding. During transvaginal ultrasound, a colonic solid, hypervascularized mass of 23 × 26 mm was visualized. As a result of this incidental finding, the patient underwent a sigmoidectomy, with a final diagnosis of intestinal schwannoma. Transvaginal ultrasound is today one of the most useful and accurate diagnostic tools in the assessment of gynecological disorders. However, the proximity of other pelvic structures makes it possible to evaluate the presence of nongynecological conditions. This fact should encourage gynecologists to systematize the transvaginal ultrasound procedure.

Esophageal Schwannoma: An Important Differential Diagnosis for Esophageal Subepithelial Lesions

Esophageal schwannoma is a rare tumor and is classified as one of the esophageal subepithelial lesions (SELs). Endoscopic ultrasound (EUS) evaluation is the gold standard for evaluating subepithelial lesions. Differentiation through EUS-guided fine needle aspiration is sometimes important to exclude lesions with malignant potential. Immunohistochemistry differentiates schwannoma from other subepithelial lesions. Strong and diffuse positivity for S100 is characteristic. The decision for conservative management versus endoscopic or thoracoscopic intervention is made based on the tumor size, location, and symptoms.

Natural history of gastrointestinal schwannomas

Background and study aims  Data are lacking on the natural history of gastrointestinal tract schwannomas. We aimed to study the natural history of all gastrointestinal schwannomas including location, diagnosis, management, and long-term outcomes. Patients and methods  Patients with a pathological diagnosis of gastrointestinal schwannoma between January 2000 and March 2020 were identified. Data on baseline demographics, presentations, associated malignancies, malignant transformation, treatment, and recurrence were collected. Results  Our cohort consisted of 44 patients with a mean age of 58.6 years, with 63.6 % women and 84.1 % White. The stomach (38.6 %) was the most common location followed by the colorectum (31.8 %). Only 22.7 % of patients were symptomatic and 22.0 % had a personal history of other malignancies. Tissue diagnosis was obtained via endoscopy in 47.7 % and from surgical pathology in 52.3 %. On histology, 65.9 % of the tumors were solid, 11.4 % had mixed features, and 2.3 % had necrosis. SP100 was tested in all but one patient and was positive in all. Mean Ki-67 in 12 patients with tumors measuring ≥ 2 cm was 3.0 % indicating a low proliferation rate. Of the patients, 77.3 % had surgery and 18.2 % underwent endoscopic resection. At a mean follow-up of 5.0 ± 4.31 years, there was no malignant transformation, recurrence or mortality associated with gastrointestinal schwannomas. Conclusions  Gastrointestinal schwannomas are diagnosed in the fifth to sixth decade with predominance in women and Whites. They are benign, mostly asymptomatic, and diagnosed incidentally. Asymptomatic gastrointestinal schwannomas including lesions ≥ 2 cm in size do not appear to need further monitoring or intervention. Patients with them should be counseled to remain up to date with routine screening guidelines pertaining to the colon, breast, and lung cancer due to the high incidence of concomitant malignancy.

Artificial intelligence-based diagnosis of upper gastrointestinal subepithelial lesions on endoscopic ultrasonography images

BACKGROUND

Endoscopic ultrasonography (EUS) is useful for the differential diagnosis of subepithelial lesions (SELs); however, not all of them are easy to distinguish. Gastrointestinal stromal tumors (GISTs) are the commonest SELs, are considered potentially malignant, and differentiating them from benign SELs is important. Artificial intelligence (AI) using deep learning has developed remarkably in the medical field. This study aimed to investigate the efficacy of an AI system for classifying SELs on EUS images.

METHODS

EUS images of pathologically confirmed upper gastrointestinal SELs (GIST, leiomyoma, schwannoma, neuroendocrine tumor [NET], and ectopic pancreas) were collected from 12 hospitals. These images were divided into development and test datasets in the ratio of 4:1 using random sampling; the development dataset was divided into training and validation datasets. The same test dataset was diagnosed by two experts and two non-experts.

RESULTS

A total of 16,110 images were collected from 631 cases for the development and test datasets. The accuracy of the AI system for the five-category classification (GIST, leiomyoma, schwannoma, NET, and ectopic pancreas) was 86.1%, which was significantly higher than that of all endoscopists. The sensitivity, specificity, and accuracy of the AI system for differentiating GISTs from non-GISTs were 98.8%, 67.6%, and 89.3%, respectively. Its sensitivity and accuracy were significantly higher than those of all the endoscopists.

CONCLUSION

The AI system, classifying SELs, showed higher diagnostic performance than that of the experts and may assist in improving the diagnosis of SELs in clinical practice.

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.

Clinical and Molecular Characteristics of Rare Malignant Tumors of Colon and Rectum

Simple Summary

Tumors of colon and rectum other than adenocarcinomas represent a neglected issue from clinical and laboratory points of view because of their rarity. In this review, we summarize and describe the rare histologic entities occurring in colon and rectum. Clinical and pathologic characteristics, prognostic behavior, treatments, and altered genes are reported to provide readers with a paramount and comparative perspective. In relation to this, we propose that improvements in registries and multidisciplinary research are warranted to ameliorate their management.

Abstract

The most frequent form of colorectal cancer is represented by adenocarcinoma being about 98% of tumor histological types. However, other rare histotypes can be found in colon and rectum (adenosquamous, goblet cell adenocarcinoma, lymphoma, medullary carcinoma, melanoma, mesenchymal, neuroendocrine, plasmacytoma, signet ring, squamous tumors). Altogether, these forms account for less than 2% of colorectal tumors. There are no specific diagnostic or therapeutic recommended approaches and most of the information available from literature derives from small and retrospective clinical series. In the present study, we provide a paramount and updated view on clinical and biologic characteristics of rare colorectal tumors.

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.

Cytomorphological and immunocytochemical diagnosis of an oesophageal mass in a 62-year-old female with dysphagia

Oesophageal schwannoma is an extremely rare benign neoplasm. Cytological diagnosis of oesophageal schwannoma has been sporadically reported in the literature. Herein, we present a case of oesophageal schwannoma in an older woman that could be accurately diagnosed based on endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) cytology accompanied by cell block immunocytochemistry.

Plexiform fibromyxoma: a clinicopathological and immunohistochemical analysis of two cases with a literature review

OBJECTIVE

This article aimed to study the clinicopathological features, immunophenotypes, and differential diagnoses of plexiform fibromyxoma (PF).

METHODS

We searched clinical and pathology databases of our hospital for patients with histologically confirmed PF from 2007 to 2020 and reviewed the relevant English and Chinese language literature.

RESULTS

Two cases of PF were identified, a 67-year-old woman and a 23-year-old man. Both patients presented with melena and anemia and underwent partial gastrectomy. Histologically, the tumors exhibited a plexiform growth pattern in the gastric submucosa and the presence of bland-looking spindle cells in the fibromyxoid stroma with the formation of small blood vessels. Immunohistochemically, the two cases were strongly positive for vimentin, smooth muscle actin, and muscle-specific actin and negative for CD117, discovered on gastrointestinal stromal tumors protein 1, CD34, CD10, S100, desmin, H-caldesmon, estrogen receptor, progesterone receptor, β-catenin, and cytokeratin.

CONCLUSIONS

PF is a rare mesenchymal tumor of the stomach that can be distinguished from other gastrointestinal mesenchymal tumors based on its distinctive morphology and immunophenotype.

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.

Jejunal schwannoma detected by video capsule endoscopy

We present a rare case of a 60-year-old woman with jejunal schwannoma. This is the first case of intestinal schwannomas detected by video capsule endoscopy. Characteristic endoscopic and immunohistochemical pictures are presented with a brief literature review.

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.

Comparative Pathology of the Peripheral Nervous System

The peripheral nervous system (PNS) relays messages between the central nervous system (brain and spinal cord) and the body. Despite this critical role and widespread distribution, the PNS is often overlooked when investigating disease in diagnostic and experimental pathology. This review highlights key features of neuroanatomy and physiology of the somatic and autonomic PNS, and appropriate PNS sampling and processing techniques. The review considers major classes of PNS lesions including neuronopathy, axonopathy, and myelinopathy, and major categories of PNS disease including toxic, metabolic, and paraneoplastic neuropathies; infectious and inflammatory diseases; and neoplasms. This review describes a broad range of common PNS lesions and their diagnostic criteria and provides many useful references for pathologists who perform PNS evaluations as a regular or occasional task in their comparative pathology practice.

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.

Rare Case of a Transverse Colon Schwannoma

Schwannomas are tumors comprised of schwann cells of the peripheral nervous system and infrequently present in the gastrointestinal tract. Transverse colon schwannomas are an even more rare subtype of gastrointestinal schwannomas. This study presents the case of a transverse colon schwannoma, in addition to presenting a literature review.

A Rare Case of Gastric Schwannoma: A Case Report and Literature Review

In general, schwannoma is a benign and slow-glowing neoplasm that rarely occurs in the gastrointestinal tract as a submucosal tumor (SMT), with the most common site being the stomach. As gastric schwannoma (GS) is a rare tumor, there is limited data in the literature about its clinical features. The diagnosis of schwannoma can only be made by pathological examination with positive staining for S-100 protein. It is necessary to obtain an accurate diagnosis to introduce optimal treatment options preoperatively. However, a precise diagnosis of GS is difficult, even with modern imaging techniques. On the other hand, a complete resection with a negative surgical margin (R0) of GS is considered the best treatment, with an excellent prognosis. We present a case of a 66-year-old female patient who underwent laparoscopic-assisted wedge gastrectomy for gastric SMT, pathologically diagnosed as GS, with positive staining for S-100 protein and negative for c-kit and CD34. At 12-month follow-up after surgery, there was no recurrence or metastasis of GS. Our treatment is appropriate and effective in case of GS exceeding 50 mm.

Gastric schwannoma: a diagnosis that should be known in 2019

Gastric schwannoma (GS) is a rare neoplasm of the stomach deriving from Schwann cells of the peripheral nerves in 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. Preoperatively, GSs are difficult to differentiate from other mesenchymal tumors, such as gastrointestinal stromal tumor (GIST) or leiomyoma, which develop from mesenchymal stem cells. The optimal management of GS is based on the symptoms of the patient, tumor size and histologic grading. Here, we report the case of a GS in a 73-year-old female who underwent a wedge gastric resection following a clinical diagnosis of GIST. A histological and immunohistochemical study was performed excluding the misdiagnosis of GIST. The histomorphological features of the lesion and absence of c-Kit and strong positivity of S100 indicated the diagnosis of GS.

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.

Laparoscopic resection of gastric schwannoma: A case report

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This is one of only 220 cases of reported cases of gastric Schwannoma.

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This is one of the very few cases of these rare tumors that has been managed with a laparoscopic approach.

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We present images of the preoperative evaluation (CT) and of the laparoscopic approach (intraoperative photos).

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The patient has over a one-year follow-up and the patient is in perfect condition with no evidence of disease.

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We accompany the case report with a thorough current review on this subject.

Introduction

Gastric schwannomas are an extremely rare presentation of mesenchymal tumors originating from Schwann cells, accounting for 0.2% of all gastric tumors. Patients are usually asymptomatic, so these tumors are frequently detected incidentally.

Presentation of case

68-year old male patient found to have a 5 cm mass in the lesser curvature of the stomach. After a careful preoperative evaluation, complete laparoscopic resection was performed. Pathology review confirmed a completely resected gastric Schwannoma. The patient’s recovery was uneventful. At a one-year follow-up he remains asymptomatic and with no evidence of disease.

Discussion

We present the uncommon case of a gastric schwannoma that was appropriately treated with a laparoscopic approach and present a current literature review focusing on diagnostic and treatment methods of these rare tumors.

Conclusion

Schwannomas should be included in the differential diagnosis of gastric tumors and can be appropriately treated with a laparoscopic approach.

The malignancy among gastric submucosal tumor

The origin and characteristics of most submucosal tumors (SMTs) cannot easily be confirmed by gastrointestinal endoscopy or other radiological examinations. Excluding GISTs, for those other gastric SMTs, most of which are deemed benign, the necessity and timing of intervention has been ignored. Thus, the malignancy of gastric SMTs still remains unknown. In order to summarize the malignancy of these gastric SMTs, we reviewed literatures and analyzed cases of gastric SMTs including heterotopic pancreas, leiomyoma, schwannoma, glomus tumor, hemangioendothelioma, granular cell tumor (GCT), lipoma, hemangiopericytoma, lymphangioma and neurofibroma. In these literatures, there are cases of malignancy among heterotopic pancreas, leiomyoma, schwannoma, glomus tumor, hemangioendothelioma and GCT. As a result, it suggests that although most of gastric SMTs are considered benign, there are still possibilities of malignancy, which requires our attention, even active intervention and long-term follow-up.

Clinical characteristics and surgical treatment of schwannomas of the esophagus and stomach: A case series and systematic review

BACKGROUND

Gastrointestinal schwannomas are slow-growing benign mesenchymal neoplasms that originate from Schwann cells of the nerve sheath of Auerbach´s plexus or less frequently from Meissner´s plexus. The main differential diagnosis of gastric schwannomas are the gastrointestinal stromal tumors (GISTs), which are classified by their immunohistochemistry. The treatment of choice for gastric schwannomas is surgery where laparoscopy plays an important role. Wedge resection, subtotal or total gastrectomy can be done. In its counterpart, esophageal schwannomas are benign tumors of the esophagus that are very uncommon since they comprise less than 2% of all esophageal tumors. The main differential diagnosis is the leiomyoma which corresponds to the most common benign esophageal tumor, followed by GIST. The treatment consists on tumoral enucleation or esophagectomy.

AIM

To review the available literature about gastrointestinal schwannomas; especially lesions from de stomach and esophagus, including diagnosis, treatment, and follow up, as well as, reporting our institutional experience.

METHODS

A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes guidelines. The following databases were used for reviewing process: PubMed, Ovid, MEDLINE, and Scopus. Only English language manuscripts were included. All gastrointestinal schwannomas specifically located in the esophagus and stomach were included. Cases that did not report long-term follow-up were excluded.

RESULTS

Gastric localization showed a higher prevalence in both, the literature review and our institution: 94.95% (n = 317) and 83% (n = 5) respectively. With a follow-up with disease-free survival greater than 36 mo in most cases: 62.01% (n = 80) vs 66.66% (n = 4). In both groups, the median size was > 4.1 cm. Surgical treatment is curative in most cases

CONCLUSION

Schwannoma must be taken into account in the differential diagnosis of gastrointestinal mesenchymal tumors. It has a good prognosis, and most are benign. A disease-free survival of more than 36 mo can be achieved by surgery.

Case Report: Schwannoma of the sigmoid colon: a case report of a rare colonic neoplasm and review of literature

Background: Schwannomas are tumors originating in Schwann cells of the peripheral nerve system and uncommonly develop in the gastrointestinal tract. Sigmoid colon schwannomas are very rare and only 28 cases have been reported. This study aims to report a case of a sigmoid colon schwannoma and present a literature review.

Case report: We report a case of a 66-year-old female with asymptomatic sigmoid colon schwannoma. The patient underwent a screening colonoscopy and about 4cm sized submucosal tumor was identified at the sigmoid colon. A colonoscopic biopsy was performed and the microscopic exam revealed an ulcerated lesion with a proliferation of fibroblast-like spindle cells beneath ulcer, which was insufficient for diagnosis. Abdominopelvic computerized tomography (CT) scan showed a well-defined, well-enhancing, round shaped and slightly heterogenous mass at the sigmoid colon. No distant metastasis was identified in abdominopelvic CT and chest CT scans. Carcinoembryonic antigen level was within a normal range (1.33ng/mL). The patient underwent laparoscopic anterior resection. Immunohistochemical staining of the resected specimen showed positivity for S-100 protein in tumor cells and schwannoma was diagnosed post-surgically. Surgical resection margins were free from tumor and no regional lymph node metastasis was reported.

Conclusion: Colon schwannomas are rare diseases. Most cases of colon schwannomas are accidentally identified during screening colonoscopy. The tumors usually present as submucosal masses and colonoscopic biopsies are mostly non-diagnostic. Surgical resection is required, and definitive diagnosis is made by confirming S-100 positive tumor cells in immunohistochemical analysis. Most cases are benign; a few cases have been reported to be malignant. Surgical resection with free negative margins is the treatment of choice

Esophageal schwannomas: A rarity beneath benign esophageal tumors a case report

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Esophageal Schwannoma is a rare tumor with only few cases reported in the literature.

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In general, Schwanommas are rarely found in the gastrointestinal tract.

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Esophagic schwanommas is the least common gastrointestinal form of presentation.

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The knowledge about a new case of esophagic schwanomma, impacts in obtaining more information about the clinical course and surgical treatment of this tumor.

Introduction

Esophageal Schwannoma is a rare tumor that represents the least frequent mesenchymal tumor of the esophagus and represents a condition with only a few cases reported in the literature

Presentation of a case

We report a 40-year-old female with a 5 years history of gastroesophageal reflux, repeated history of pharyngitis, odynophagia that culminated in progressive oropharyngeal dysphagia to solids. A barium esophagogram revealed a filling defect in the superior and middle thirds of the esophagus. Upper gastrointestinal endoscopy showed a smooth elevated lesion in the upper third of the esophagus, impossible to resect by this mean. An open left cervical approach revealed an 80 × 45 × 20 mm large tumor, which was resected.

Discussion

In general, Schwanommas are rarely found in the gastrointestinal tract (GI), while the great majority occur in the stomach, esophagic is the least common GI form of presentation.

Conclusion

The knowledge about a new case, impacts in obtaining more information about the clinical course and surgical treatment of this tumor.

Gastric schwannoma: report of two cases and review of the literature

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Schwannomas are mesenchymal tumors.

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Schwannomas are benign, slow-growing and usually asymptomatic tumors, but in some cases bleeding, epigastric pain and palpable mass may occur.

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Preoperative diagnosis is challenging due to the difficulty of differentiation from other sub-mucosal tumors.

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The size and location of the tumor, as well as its relation to the surrounding organs, are essential factors in determining the type of operation.

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Local extirpation, wedge resection, partial, subtotal or even total gastrectomy, are all acceptable operations.

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Gastric schwannomas have a good prognosis.

Introduction

Gastrointestinal schwannomas are benign, slow-growing and usually asymptomatic tumors. In some cases bleeding, epigastric pain and palpable mass may be occurring. Preoperative diagnosis is challenging due to the difficulty of differentiation from other submucosal tumors. Diagnosis is most often provided through the histology report.

Case presentation

In this study we report two cases of gastric tumors with the suspicion of a GIST preoperatively but histologically confirmed to be gastric schwannomas. Two patients of our study gave to us their written consent for publication. Research work has been reported with the PROCESS criteria.

Discussion

Surgical resection should be considered the mainstay of treatment in patients with gastric schwannomas. Possible complications such as bleeding or pyloric stenosis can be presented. The size and location of the tumor, as well as its relation to the surrounding organs, are essential factors in determining the type of resection.

Conclusion

Gastric schwannomas are usually presented us submucosal mass. Preoperative diagnosis is challenging due to the difficulty of differentiation from other submucosal tumors. Endoscopic Esophagogastroduodenoscopy with biopsy and endoscopic ultrasound is essential to determine the nature of these lesions. Resection of the lesion in healthy borders is the treatment of choice. Patho-logical examination usually revealed positive S-100 protein and negative CD34, CD117, Actin and desmin strains.