Korean J Helicobacter Up Gastrointest Res.  2021 Jun;21(2):156-160. 10.7704/kjhugr.2020.0061.

C-kit-negative Extragastrointestinal Stromal Tumor Originating in the Mesentery Misdiagnosed as an Ovarian Tumor before Surgery

• Lim J
• Baeg MK
• Ahn S
• Ha MH
• Ko SH
• Kwon H
• Han J

• KMID: 2516636
• DOI: http://doi.org/10.7704/kjhugr.2020.0061

Abstract

Gastrointestinal stromal tumors (GISTs) are rare digestive system malignancies with extragastrointestinal stromal tumors (EGISTs) being even less. Diagnosing GISTs usually requires the identification of c-kit (CD117) expression by immunohistochemical staining. A 53-year-old woman complaining of dyspepsia was referred for the evaluation of a 1.5-cm extrinsic compression at the greater curvature of the proximal antrum. EUS revealed a multiseptated mass with positive Doppler findings. Abdominal CT showed that she harbored a large, 20-cm mass in her abdominal cavity, most likely arising from the right ovary. Surgery revealed a hypervascular tumor arising from the mesentery and attached to the gastric lesser curvature. Pathological examination revealed negativity for c-kit, but positivity for the protein “Discovered on GIST-1” (DOG1), confirming the EGIST diagnosis. Herein, we report this rare case of a c-kit-negative EGIST originating in the mesentery, which was diagnosed based on staining for DOG1.

Keyword

C-kit protein; DOG-1 protein; Gastrointestinal stromal tumor; Mesentery