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.
Adult ; Aged ; Diagnosis, Differential ; Endosonography ; Female ; Gastric Fundus/pathology ; Gastrointestinal Stromal Tumors/*diagnosis/diagnostic imaging/pathology ; Humans ; Male ; Middle Aged ; Neoplasm Staging ; Neurilemmoma/*diagnosis/diagnostic imaging/pathology ; Retrospective Studies ; Stomach Neoplasms/*diagnosis/diagnostic imaging/pathology

Primary malignant small bowel tumor as a rare kind of intestinal tumor is associated with a poor prognosis. The pathological types were various and complicated, such as adenocarcinoma, neuroendocrine tumor, malignant lymphoma, and malignant stromal tumor. The atypical early stage symptom resulted in difficult diagnosis at early stage, high misdiagnosis rate and lack of standard therapy schemes and means. In the past, X-ray, CT, MRI, and PET-CT were the main examination methods for primary small bowel tumor. However, with the development of radiology, a series of new diagnosis methods, including electronic enteroscopy, capsule endoscopy, multi-slice spiral CT enteroclysis and so on, promotes the diagnosis accurate rate. Surgery is still the most important method in the small bowel tumor treatment, and the alternative of the surgical method should depend on the tumor location, size and relationship with the adjacent organs. Application of the laparoscopic surgery for the small bowel tumor is still in the initial stage. Besides, some researches have confirmed that chemotherapy, radiotherapy, target therapy and endocrinotherapy have effects on the specific kind of small bowel tumor. Therefore this article will review the epidemiology, pathology, diagnosis and treatment of the primary malignant small bowel tumors.
Adenocarcinoma ; diagnosis ; epidemiology ; pathology ; therapy ; Capsule Endoscopy ; Gastrointestinal Stromal Tumors ; diagnosis ; epidemiology ; pathology ; therapy ; Humans ; Intestinal Neoplasms ; diagnosis ; epidemiology ; pathology ; therapy ; Intestine, Small ; diagnostic imaging ; pathology ; Laparoscopy ; methods ; Lymphoma ; diagnosis ; epidemiology ; pathology ; therapy ; Neuroendocrine Tumors ; diagnosis ; epidemiology ; pathology ; therapy ; Tomography, Spiral Computed