Histomorphological spectrum of gastrointestinal stromal tumors – An institutional experience in a series of seven cases

Abstract

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the abdominal area. They can involve any portion of GI tract, omentum, mesentery, retroperitoneum, and other sites. The tumor is seen to be arising from interstitial cell of Cajal, the pacemaker cells of the GI muscularis propria. About 60% of GISTs occur in stomach. More than 95% of GISTs are positive for immunohistochemical marker Crohn’s disease (CD) CD117. Still in 5% of cases, CD117 expression is not found. Although, in these cases, staining with discovered on GIST-1 (DOG1, also known as ANO1) can be helpful in confirming the diagnosis of GIST histomorphological diagnosis remains the gold standard diagnostic modality with CD 117 positivity leading to more confirmation. Tumor size and mitotic count remain the main factors in the risk categorization of tumors. Furthermore, every spindle cell lesion should undergo CD117 immunohistochemistry markers as an initial workup.