Immunohistochemical Expression in Gliomas - CD117 in a Prognostic and Theranostic Vision

Gliomas are a varied group of infiltrative neoplasms, They are mostly high grade, with a short survival time and less amenable for surgical treatment. . Hence there is a dire need for chemotherapy. CD117 is a protooncogene encoded tyrosine kinase receptor. It is expressed in some normal tissues and in neoplasms like gastrointestinal stromal tumours (GIST), where treatment with inhibitors of tyrosine kinase receptor namely imatinib was proved successful. Likewise this study evaluates the expression of CD117 in gliomas and its role as a as diagnostic and theranostic tool. Materials and methods: This is a retrospective two year study. A total of 836 cases of neuro biopsies were received out of which 263 cases were gliomas. Among them 50 representative cases were selected grade wise and evaluated immunohistochemically for CD117 expression. Results: Incidence of gliomas was 31.4 % (263 cases) in our study. Glioblastoma multiforme, WHO GRADE IV tumour was the most common type. Pilocytic astrocytoma was the most common GRADE Itumour. Anaplastic astrocytoma was the most common Grade III tumour. CD117 was expressed in 54 % of total cases and was expressed maximum in high grade tumours (66.8 %) compared to low grade tumours. Significant CD117 expression was seen in cases with high cellularity and marked nuclear pleomorphism. Conclusion: Our study shows CD117 is expressed remarkably in high grade gliomas than low grade. Hence CD117 can be used as a perfect tool to differentiate high grade tumours and subject them to chemotherapy with tyrosine kinase inhibitors, namely imatinib. . Hence our study opens the vision on targeted therapy in high grade gliomas.