Clin Endosc.  2016 Nov;49(6):548-554. 10.5946/ce.2015.115.

Endosonographic Features of Gastric Schwannoma: A Single Center Experience

• Yoon JM
• Kim GH
• Park DY
• Shin NR
• Ahn S
• Park CH
• Lee JS
• Lee KJ
• Lee BE
• Song GA

• KMID: 2383451
• DOI: http://doi.org/10.5946/ce.2015.115

Abstract

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.

Keyword

Endosonography; Mesenchymal tumor; Schwannoma; Stomach

MeSH Terms

Busan
Endosonography
Gastrointestinal Stromal Tumors
Neurilemmoma*
Retrospective Studies
Stomach

Figure

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  Fig. 1. A case of gastric schwannoma (case 24). (A) Endoscopy reveals a subepithelial mass in the middle third of the stomach. (B) Endoscopic ultrasonography reveals that the mass is heterogeneous with an echogenicity lower than that of the surrounding normal proper muscle layer. The lesion size is 35×30 mm, and marginal haloes (arrow) are visible. (C) Microscopic examination reveals a relatively circumscribed mass that is composed of variably organized spindle cells surrounded by patches of lymphoid infiltration (arrowheads; H&E stain, ×40). The tumor cells are strongly positive for S-100 protein (boxed area, anti-S-100 antibody stain, ×400).

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