Stains & CD markers
CD117 / KIT
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PubMed Search: CD117 / KIT
See Also: Stains chapter
CD117 / KIT
Editorial Board Members: Alexa J. Siddon, M.D., Wei Chen, M.D., Ph.D.
Last author update: 9 June 2022
Last staff update: 9 June 2022
Copyright: 2003-2024, PathologyOutlines.com, Inc.
PubMed Search: CD117 / KIT
See Also: Stains chapter
Table of Contents
Definition / general | Essential features | Terminology | Pathophysiology | Interpretation | Uses by pathologists | Microscopic (histologic) images | Positive staining - normal | Positive staining - disease | Negative staining | Sample pathology report | Board review style question #1 | Board review style answer #1Cite this page: Frauenfeld L, Schürch CM. CD117. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cdmarkerscd117.html. Accessed April 25th, 2024.
Definition / general
- Proto-oncogene activated in gastrointestinal stromal tumors (GISTs) (Cureus 2022;14:e20868, Appl Immunohistochem Mol Morphol 2005;13:205)
- Aka c-kit, KIT, stem cell factor receptor, mast cell growth factor
- Gene at 4q11-21
- Class III receptor tyrosine kinase (Appl Immunohistochem Mol Morphol 2005;13:205)
- 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 (Appl Immunohistochem Mol Morphol 2005;13:205)
Essential features
- Proto-oncogene activated in GISTs (Cureus 2022;14:e20868)
- Gene at 4q11-21
- Class III receptor tyrosine kinase
- Highlights mast cells (normal and abnormal) in the assessment of mast cell neoplasms
Terminology
- CD117 / KIT
- Also known as c-kit, stem cell factor receptor, mast cell growth factor (Appl Immunohistochem Mol Morphol 2005;13:205)
Pathophysiology
- Has activating or gain of function mutations in most GISTs, often at exon 11, less often at exons 9 and 13 (Hum Pathol 2002;33:484, Cancer Med 2020;9:6485, Cureus 2022;14:e20868)
- Tyrosine kinase activity of c-kit in GIST and BCR-ABL overexpression in chronic myeloid leukemia (CML) are inhibited by imatinib mesylate (Gleevec, STI571), a tyrosine kinase inhibitor used to treat these diseases (Clin Cancer Res 2022;28:1672)
- Mutated in mastocytosis, typically the D816V mutation
Interpretation
- Cytoplasmic staining
Uses by pathologists
- Confirming diagnosis of GIST (also see Positive staining - disease) (Cureus 2022;14:e20868)
- Staining of mast cells
- Staining of myeloid stem cells (myelodysplastic syndrome [MDS], acute myeloid leukemia [AML]: estimating quantity of blasts)
Microscopic (histologic) images
Contributed by Debra L. Zynger, M.D. and Andrey Bychkov, M.D., Ph.D.
Seminoma with IHC
Testis
GIST
Positive staining - normal
- Interstitial cells of Cajal, hematopoietic progenitor cells, melanocytes, embryonic / fetal brain, endothelium, gonads, mast cells, breast epithelium, germ cells (Appl Immunohistochem Mol Morphol 2005;13:205)
Positive staining - disease
- Acute myeloid leukemia (Gastroenterology Res 2022;15:39, Appl Immunohistochem Mol Morphol 2005;13:205)
- Adenoid cystic carcinoma of salivary gland (strong staining)
- Angiomyolipoma (Am J Surg Pathol 2002;26:493)
- Angiosarcomas (50%) (Appl Immunohistochem Mol Morphol 2005;13:205)
- Epithelioid sarcoma (Appl Immunohistochem Mol Morphol 2005;13:205)
- Ewing sarcoma (Appl Immunohistochem Mol Morphol 2005;13:205)
- Gastrointestinal stromal tumor (Appl Immunohistochem Mol Morphol 2005;13:205)
- Hodgkin lymphoma (some Reed-Sternberg cells)
- Intra-abdominal fibromatosis (depends on antibody used) (Am J Surg Pathol 2001;25:549)
- Leiomyosarcoma (Appl Immunohistochem Mol Morphol 2005;13:205)
- Mast cell diseases (also positive for tryptase, CD43, CD68)
- Melanoma (Arch Pathol Lab Med 2006;130:343)
- Mesenteric fibromatosis (variable) (Am J Surg Pathol 2002;26:1296)
- Metanephric adenosarcoma (Am J Surg Pathol 2001;25:1451)
- Nasopharyngeal angiofibroma (Arch Pathol Lab Med 2003;127:1480)
- Osteosarcoma (Appl Immunohistochem Mol Morphol 2005;13:205)
- Rhabdomyosarcoma
- Seminomas / dysgerminomas (Hum Pathol 2002;33:1182, Appl Immunohistochem Mol Morphol 2005;13:205)
- Small cell carcinoma of the lung (Appl Immunohistochem Mol Morphol 2005;13:205)
- Synovial sarcoma (~10%, usually cytoplasmic staining)
- Thymic carcinoma (Appl Immunohistochem Mol Morphol 2005;13:205)
- 50% of solid pseudopapillary tumor (Mod Pathol 2006;19:1157)
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 (Am J Surg Pathol 2002;26:486)
Sample pathology report
- Gastric biopsy:
- Gastrointestinal stromal tumor (see comment)
- Comment: Infiltrates of a well circumscribed spindle cell tumor with few mitoses (2 / 5 mm2). Immunohistochemically, the tumor is CD117+, DOG1+ and CD34+.
Board review style question #1
Which of the following is the most likely underlying mutation in this gastrointestinal stromal tumor (staining with the associated protein for this mutation)?
- ALK
- KIT
- PDGFRA
- PDGFRB
- SDHB
Board review style answer #1
