CD Markers
CD117 / KIT

Topic Completed: 1 August 2013

Revised: 9 September 2019

Copyright: 2003-2018,, Inc.

PubMed Search: CD117[title]

Nat Pernick, M.D.
Page views in 2018: 22,182
Page views in 2019 to date: 21,402
Cite this page: Pernick N. CD117. website. Accessed October 16th, 2019.
Definition / general
  • Summary: proto-oncogene activated in GIST tumors
  • Aka c-kit, KIT, stem cell factor receptor
  • Gene at 4q11-21
  • Receptor for kit protein, a 145 kD tyrosine kinase growth factor receptor protein important for development and survival of mast cells, hematopoietic stem cells, melanocytes, germ cells, interstitial cells of Cajal
  • Has activating or gain of function mutations in most GIST tumors, often at exon 11, less often at exons 9 and 13 (Hum Pathol 2002;33:484)
  • Tyrosine kinase activity of c-kit in GIST and bcl-abl overexpression in CML are inhibited by imatinib mesylate (Gleevec, STI571), a tyrosine kinase inhibitor used to treat these diseases (Hum Pathol 2002;33:466)
Uses by pathologists
  • Confirming diagnosis of GIST (but see other CD117+ tumors below)
  • Possibly confirm chronic intestinal pseudo-obstruction (Am J Surg Pathol 2003;27:228)
  • Should be strong and diffuse cytoplasmic staining, like the positive control
Microscopic (histologic) images

Images hosted on PathOut server:

Contributed by
Debra L. Zynger, M.D.

Seminoma with IHC



Contributed by Andrey Bychkov, M.D., Ph.D.,
Kameda Medical Center


Images hosted on other servers:
Missing Image

GIST vs. solitary fibrous tumor

Missing Image

Malignant stromal tumor
of gallbladder (figure 4)

Positive staining - normal
  • Interstitial cells of Cajal, hematopoietic progenitor cells, melanocytes, embryonic/fetal brain, endothelium, gonads, mast cells, breast epithelium, germ cells
Positive staining - tumors
  • AML, angiomyolipoma (Am J Surg Pathol 2002;26:493), angiosarcomas (50%), clear cell sarcoma, CML, epithelioid sarcoma, Ewing sarcoma, gastrointestinal autonomic tumor (GANT), gastrointestinal stromal tumor (GIST), granulocytic sarcoma, Hodgkin lymphoma (some Reed-Sternberg cells), intraabdominal fibromatosis (depends on antibody used, Am J Surg Pathol 2001;25:549), mast cell disease (also positive for tryptase, CD43, CD68); melanoma, mesenteric fibromatosis (variable, Am J Surg Pathol 2002;26:1296), metanephric adenosarcoma (Am J Surg Pathol 2001;25:1451), omental mesenchymal tumor, osteosarcoma, rhabdomyosarcoma, sclerosing mesenteritis (variable), seminomas /dysgerminomas, small cell lung cancer (Hum Pathol 2002;33:1182), synovial sarcoma (~10%, usually cytoplasmic staining), adenoid cystic carcinoma of salivary gland (strong staining)
Negative staining
  • Alveolar soft part sarcoma, desmoplastic small round cell tumor, glomus tumor, leiomyoma (retroperitoneal, colorectal), leiomyosarcoma, myxoma (cardiac), schwannoma (colorectal), smooth muscle tumor of uncertain malignant potential, solitary fibrous tumor
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