Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the gastrointestinal (GI) tract. Before the current definition of GIST evolved, GISTs were classified as benign or malignant smooth muscle tumours including true smooth muscle tumours (leiomyomas, leiomyoblastomas, leiomyosarcomas) and neuronal tumours (schwannomas).1,2
In the past 10 years, a new definition of GIST has been widely accepted that includes distinct morphology, location, and immunohistochemical staining criteria.1,3,4 GISTs are mesenchymal neoplasms, with spindle cell or epithelioid morphology. GISTs are located primarily in the GI tract, omentum, and mesentery. The defining molecular marker of GIST is the KIT tyrosine kinase receptor (also known as c-Kit).
1. Fletcher CDM, Berman JJ, Gorstein F, et al. Diagnosis of gastrointestinal stromal tumors: a consensus approach. Hum Pathol. 2002;33:459-465.
2. Connolly EM, Gaffney E, Reynolds JV. Gastrointestinal stromal tumours,Br J Surg. 2003;90:1178-1186.
3. Miettinen M, Lasota J. Gastrointestinal stromal tumors--definition, clinical, histological, immunohistochemical, and molecular genetic features and differential diagnosis. Virchows Arch. 2001;438:1-12.
4. Nilsson B, Bumming P, Meis-Kindblom JM, et al. Gastrointestinal stromal tumors: The incidence, prevalence, clinical course, and prognostication in the preimatinib mesylate era. Cancer. 2005;103:821-829