Gastric Schwannoma: A Case Report and Review of Literature

Abstract

Schwannomas are usually benign, slow growing tumors, that originate from any nerve that has a Schwann cell sheath. Here, we report the case of a 40 year-old female patient with an incidentally noted submucosal gastric tumor while being evaluated for cervical lymphadenopathy as a part of workup for lymphoma. She underwent sleeve resection of the stomach under suspicion of a gastrointestinal stromal tumor, but postoperative histopathological and immunohistochemical findings confirmed the diagnosis of shwannoma. Although schwannomas are mostly benign, they are often indistinguishable preoperatively from malignant tumors such as gastrointestinal stromal tumors. Therefore, resection is the treatment of choice for all such tumors.Keywords Gastric schwannoma . GIST . Immunohistochemistry . Sleeve resection Case ReportA 48 year old lady with cervical lymphadenopathy was subjected to ultrasound of the abdomen for ruling out splenomegaly as a part of work up for lymphoma. Ultrasound of the abdomen (Fig. 1) revealed a well defined lobulated hypoechoic mass lesion in the epigastric region located between the left lobe of liver and gastric wall. It was 4.2 × 4.1 cm in size. Computed tomography scan showed well defined uniformly enhancing gastric fundal wall mass, (Fig. 2) most likely to be GIST (gastrointestinal stromal tumour) with celiac axis and periportal nodal enlargement. The mass was partly exophytic and partly projecting into the lumen causing smooth indentation. The patient then underwent upper GI endoscopy which showed a sub mucosal bulge on the anterior wall of the fundus of the stomach. An endosonography was done using a linear scope which showed a large submucosal mixed echoic mass with few areas of necrosis in body of stomach mainly on greater curvature measurng 5 × 4 cm arising from muscularis propria. Two celiac nodes, hypoechoic round with uniform echotexture were also seen. FDG pet scan showed metabolically active tumor mostly representing GIST (Gastrointestinal stromal tumour) from body of the stomach (Fig. 3).A provisional diagnosis of submucosal mass, which could be most likely GIST, was made and fine needle aspiration cytology was done from both the lesion and the nodes with endosonoguidance. The FNA from gastric submucosal lesion showed features suggestive of spindle cell tumor while the celiac nodes showed reactive hyperplasia. A preoperative diagnosis of GIST arising from anterior wall of proximal stomach was made. The patient was subjected to laparoscopic examination which revealed an exophytic solid tumor measuring 6 × 7 cm arising from the anterior wall of the junction of body and fundus. The medial margin was at the lesser curvature and lateral margin was just short of greater curvature. In order to get a good tumor negative margin laparoscopy was converted to minilaparotomy and sleeve resection of the tumor was done using linear staplers. Histopathology revealed a submucosal tumor with features suggestive of spindle cell tumor (Fig. 4). IHC done showed positivity

Clinical Characteristics and Surgical Management of Gastrointestinal Schwannomas

“…Schwannomas are a subset of neurogenic tumors and are the majority among them [ 12 ]. Schwannomas of the gastrointestinal tract are very rare and commonly occur in the stomach (approximately 0.2% of all gastric tumors) [ 13 ]. GS occur more frequently in female patients [ 14 – 16 ], with a female-to-male ratio of 2 : 1 or higher [ 17 , 18 ].…”

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

“…In the gastrointestinal tract, GISTs constitute the largest group of mesenchymal tumours, whereas schwannomas are rare constituting only 0.2% of all gastric neoplasms. 1 Malignant transformation of a gastric schwannoma is very rare. They can arise from the fundus, body or antrum of the stomach and are commonly submucosal.…”

“…They are usually solitary lesions arising from the lesser curvature of the stomach but can arise from greater curvature also as in this case. [1][2][3] On a CT scan, a gastric schwannoma tends to be homogenous, which distinguishes it from leiomyomas and leiomyosarcomas which have heterogeneous appearance owing to areas of haemorrhage and necrosis within the tumor. 4,5 Magnetic resonance imaging (MRI) can determine the exact layer of origin and location of the tumor.…”

“…It accounts for only 0.2% of all gastric tumors, and 4% of all benign tumors of the stomach. 1 GS was first described in 1988 by Daimaru et al 2 The main differential diagnosis of a gastric submucosal schwannoma is a gastrointestinal stromal tumor (GIST) due to similar appearance on radiological imaging and endoscopy. However, treatment and prognosis for gastric schwannomas and GISTs vary in view of benign nature and excellent prognosis after resection for gastric schwannomas, whereas 10 to 30% of GISTs can have malignant behavior with recurrence of the tumor after resection.…”

Gastric schwannoma: a case report and literature review

“…1 Representing as little as 0.2% of all types of gastric tumors, gastric schwannomas are usually asymptomatic and non-malignant. 2 We herein present a rare case of a gastric schwannoma.…”