Immunohistochemical Expression of Signal Transducer and Activator of Transcription (STAT6) in Classic Hodgkin Lymphoma (CHL)

Background: Hodgkin lymphoma (HL) is a significant malignancy, with Classic Hodgkin Lymphoma (CHL) and Nodular Lymphocyte Predominant Hodgkin Lymphoma (NLPHL) being its main subtypes. STAT6, a transcription factor in the IL-4/IL-13 pathway, may aid in distinguishing between these subtypes through immunohistochemical analysis.Objective: To evaluate the diagnostic utility of STAT6 immunohistochemical expression in differentiating CHL from NLPHL.Methods: A comparative cross-sectional study was conducted on 94 lymphoma cases, including 53 CHL and 41 NLPHL cases. Tissue samples were fixed, processed, and stained with STAT6 antibody. Nuclear and cytoplasmic STAT6 expression was assessed in neoplastic cells. Statistical analysis was performed using SPSS version 25, with Fisher’s exact test applied.Results: Nuclear STAT6 expression was observed in 100% of CHL cases (53/53) and in 24.39% of NLPHL cases (10/41). Combined nuclear and cytoplasmic STAT6 expression was present in all CHL cases (53/53) but absent in NLPHL cases (0/41).Conclusion: STAT6 nuclear expression serves as a reliable marker to distinguish CHL from NLPHL, with a 100% negative predictive value for NLPHL.