Rare expression of KIT (CD117) in lymphomas: a tissue microarray study of 1166 cases
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Updated: Aug 21, 2026
Multiplexed Fluorescent Immunohistochemical Staining, Imaging, and Analysis in Histological Samples of Lymphoma
Published on: January 9, 2019
Aims:
Imatinib mesylate specifically inhibits KIT tyrosine kinase activity, and has been proven to be effective in the treatment of gastrointestinal stromal tumours. Because other KIT-expressing malignancies might benefit from Imatinib therapy, we evaluated the distribution and expression of KIT in 1166 cases of malignant lymphoma.
Materials And Results:
Tissue microarrays (TMAs) containing 824 non-Hodgkin's lymphoma (NHL) and 342 Hodgkin's lymphoma (HL) cases were immunohistochemically analysed for the expression of the KIT protein. Two KIT-positive NHLs were sequenced using polymerase chain reaction analysis. One T-cell lymphoma and one follicular lymphoma of the 747 NHL cases (0.3%) were positive for KIT. All HLs were Kit-negative. None of the KIT-positive cases showed a kit gene mutation.
Conclusions:
KIT expression is a very rare event in NHL and virtually absent in HL. In the few positive cases, the aberrant expression is not caused by a mutation in the 'hot-spots' of the kit gene, indicating that treatment of these tumours with Imatinib may be ineffective.
Insights
KIT expression is rare in non-Hodgkin's lymphoma (NHL) and absent in Hodgkin's lymphoma (HL). Aberrant KIT expression in NHL is not due to common mutations, suggesting Imatinib may not be effective for these rare cases.
Area of Science:
- Oncology
- Hematology
- Molecular Biology
Background:
- Imatinib mesylate targets KIT tyrosine kinase, proving effective in gastrointestinal stromal tumors.
- KIT expression in other malignancies is being investigated for potential Imatinib therapy benefits.
Purpose of the Study:
- To evaluate the distribution and expression of KIT in a large cohort of malignant lymphoma cases.
- To determine if KIT mutations are present in KIT-expressing lymphomas.
Main Methods:
- Immunohistochemical analysis of KIT protein expression on tissue microarrays from 1166 lymphoma cases (824 NHL, 342 HL).
- Polymerase chain reaction sequencing of KIT-positive cases to identify gene mutations.
Main Results:
- KIT expression was found in only 0.3% of non-Hodgkin's lymphoma (NHL) cases (1 T-cell lymphoma, 1 follicular lymphoma).
- All Hodgkin's lymphoma (HL) cases were negative for KIT expression.
- No KIT gene mutations were detected in the KIT-positive NHL cases.
Conclusions:
- KIT expression is a rare phenomenon in NHL and virtually absent in HL.
- The aberrant KIT expression observed in rare NHL cases is not associated with mutations in common 'hot-spots' of the kit gene.
- Imatinib therapy is unlikely to be effective for the majority of lymphomas due to the rarity of KIT expression and lack of targetable mutations.
