Onkologie. 2010:4(1):13-17

Pathological diagnostics of gastrointestinal stromal tumor

Ondřej Daum¹, Radek Šíma², Michal Michal¹

¹ Šiklův ústav patologie FN Plzeň, Univerzita Karlova v Praze, Lékařská fakulta v Plzni

² Bioptická laboratoř s.r.o., Plzeň

Gastrointestinal stromal tumor is the most frequent mesenchymal tumor of the alimentary tract, currently being defined as a tumor

composed of spindle and/or epithelioid cells presumably differentiating towards interstitial cells of Cajal. The most common location of

gastrointestinal stromal tumor is stomach followed by other sites of gastrointestinal tract. Occasional sites of occurrence are mesenterium,

omentum, retroperitoneum, gallbladder, urinary bladder, pancreas and vagina. Light microscopic examination of slides stained with

haematoxylin and eosin is highly reliable in most cases. Immunohistochemical investigation relies on expression of KIT protein (CD117),

PDGFRA and/or DOG-1, as well as absence of markers of other differentiation lineages. Molecular genetic analysis of KIT and PDGFRA

genes is useful not only for differential diagnosis, but also for prediction of therapeutic response. Nevertheless, negative results do not

exclude histologically proven diagnosis. All gastrointestinal stromal tumors should be regarded as potentially malignant with risk of

aggressive behavior being determined on the basis of location, mitotic count, and the largest diameter of the tumor.

Keywords: gastrointestinal stromal tumor, GIST, KIT, PDGFRA, imatinib, sunitinib

Published: March 1, 2010  Show citation