The intermediate filament protein synemin (SYNM) was found to be more widespread in CD117⁺ gastrointestinal stromal cell tumors (GIST) than the CD34 transmembrane phosphoglycoprotein: an immunohistochemical study

Mast Cell Concentrations in Pancreatic Disease Processes

“…Not all mast cells are both CD117 and tryptase positive 28 . CD117 (or c-kit) is not specific to mast cells and can be found on the surface of hematopoietic stem cells, interstitial cells of Cajal, and gastrointestinal stromal cell tumors 29,30 . However, given the location and morphology of the cells with positive staining, sources other than mast cells are unlikely.…”

“…28 CD117 (or c-kit) is not specific to mast cells and can be found on the surface of hematopoietic stem cells, interstitial cells of Cajal, and gastrointestinal stromal cell tumors. 29,30 However, given the location and morphology of the cells with positive staining, sources other than mast cells are unlikely. Furthermore, there is putatively a subset of mast cells in the stomach and intestine which do not contain appreciable amounts of tryptase 27 and therefore would fail to be enumerated by tryptase IHC.…”