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Friday 12 December 2003

c-kit; CD117

Definition: The proto-oncogene c-kit / CC117 is a receptor tyrosine kinase recognized to initiate essential signal transduction pathways that transmit biological signals for cellular proliferation, differentiation, and metastasis. Aberrant expression or mutation of c-kit has been shown to be involved in the pathogenesis of many cancers.

See also CD117 IHCDB

Expression in cells

- c-KIT positive spermatogonia

Expression in tumors (Exemples)

- chromophobe renal cell carcinoma (100%)
- renal oncocytoma (100%)
- adenoid cystic carcinoma

  • On cytology, adenoid cystic carcinoma has globular metachromatic PAS positive basement membrane material, myoepithelial and epithelial cells.
  • The myoepithelial cells stain positive for CK, p63, calponin, SMA, and S100. The epithelial cells stain for CK, CEA and EMA.
  • Adenoid cystic carcinoma is CK7 + / CK20 - and positive for CD117.
  • It is the most common tumor of the palate, followed by polymorphous low grade adenocarcinoma, and the second most common malignant salivary neoplasm, after mucoepidermoid carcinoma.


- KIT activating mutations in

Use in diagnosis

- Differential diagnosis between chromophobe renal cell carcinoma and the granular variant of clear cell renal cell carcinoma (15832088)

- KIT is an independent prognostic marker for pancreatic endocrine tumors. (19574886)


Expression in normal cells

- Immunohistochemical expression analysis of Cx43, Cx26, c-KIT and PlAP in contralateral testis biopsies of patients with non-seminomatous testicular germ cell tumor. Steiner M, Weipoltshammer K, Viehberger G, Meixner EM, Lunglmayr G, Schöfer C. Histochem Cell Biol. 2011 Jan;135(1):73-81. PMID: 21161545

Expression in tumors

- KIT is an Independent Prognostic Marker for Pancreatic Endocrine Tumors: A Finding Derived From Analysis of Islet Cell Differentiation Markers. Zhang L, Smyrk TC, Oliveira AM, Lohse CM, Zhang S, Johnson MR, Lloyd RV. Am J Surg Pathol. 2009 Jul 1. PMID: 19574886

- Wang HY, Mills SE. KIT and RCC Are Useful in Distinguishing Chromophobe Renal Cell Carcinoma From the Granular Variant of Clear Cell Renal Cell Carcinoma. Am J Surg Pathol. 2005 May;29(5):640-646. PMID: 15832088


- germline mutations

  • germ-line gain-of-function mutations of c-kit receptor tyrosine kinase (KIT) gene in familial gastrointestinal stromal tumors (GIST)

- somatic mutations

  • somatic gain-of-function mutations of c-kit receptor tyrosine kinase (KIT) gene in sporadic gastrointestinal stromal tumors (GIST)

- overexpression in tumors

  • colorectal neuroendocrine carcinomas: c-kit overexpression observed in a subset of colorectal neuroendocrine carcinomas (not be mediated by activating mutations) (14657715)
  • renal oncocytoma (71%) (15105658)
  • renal chromophobe renal cell carcinoma (88%) (15105658)
  • medulloblastoma (15547773)

Diagnostic use of CD117

- positive diagnosis of renal oncocytoma (71%) (15105658)
- positive diagnosis of renal chromophobe renal cell carcinoma (88%) (15105658)

Mutations - Variants

- KIT-p.D419del

  • A subset of gastrointestinal stromal tumors previously regarded as wild-type tumors carries somatic activating mutations in KIT exon 8 (p.D419del).


- Druker BJ. STI571 (Gleevec) as a paradigm for cancer therapy. Trends Mol Med. 2002;8(4 Suppl):S14-8. PMID: 11927282