A case of KIT negative extra-gastrointestinal stromal tumor arising in the greater omentum with predominant cystic formation

• Main Authors: Katsuya Nanjo, MD, Yusuke Nishimuta, MD, Mitsutoshi Miyasaka, MD, Kenji Shinozaki, MD, PhD, Daisuke Tsurumaru, MD, PhD, Kousei Ishigami, MD, PhD
• Format: Article
• Language: English
• Published: Elsevier 2021-08-01
• Series: Radiology Case Reports
• Subjects: Gastrointestinal stromal tumor; Extra-gastrointestinal stromal tumor; KIT; Greater omentum
• Online Access: http://www.sciencedirect.com/science/article/pii/S193004332100354X
• ISSN: 1930-0433

We report a rare case of KIT-negative extra-gastrointestinal stromal tumor, in a 40-year-old woman. Contrast-enhanced computed tomography and magnetic resonance imaging revealed a >15-cm mass of multiple cystic lesions in the greater omentum. Histopathological findings after surgery showed a sheet-like growth of stellate tumor cells from epithelial cells, cystic degeneration, and mucus-like stroma. Immunohistochemistry was positive for discovered on GIST-1 (DOG1) but negative for CD117 (c-kit).