GATA3 Immunohistochemical Staining in Classical Hodgkin Lymphoma and its Diagnostic Utility in Differential Diagnosis.

Objective: Classical Hodgkin lymphoma (CHL) is a common lymphoid neoplasm with a wide range of differential diagnosis. Although it has a specific immunophenotype, aberrant expression of antigens can cause problems at its diagnosis. In this study we evaluated the usefulness of GATA3 in differential diagnosis of classical Hodgkin lymphoma.

Material and method: One hundred CHL cases and a control group of 106 lymphoma cases, which include anaplastic large cell lymphoma (ALK (+) and (-)), EBV (+) large B cell lymphoma, T-cell/ histiocyte rich B cell lymphoma, primary mediastinal large B cell lymphoma, nodular lymphocyte predominant Hodgkin lymphoma and mediastinal grey zone lymphoma, were included in the study. GATA3 immunohistochemistry were applied to all cases and its nuclear expression was accepted as positive. Expression status of GATA3 was compared in between the CHL and the control group, as well as among each lymphoma subtype. In addition, whether the biopsy type effects its diagnostic performance is assessed. In CHLs relationship with EBV status and GATA3 expression is evaluated.

Results: GATA3 expression was significantly higher in CHL cases compared to the control group (p<0,001). When compared with the individual subgroups GATA3 is still found to be useful in differential diagnosis except for ALK (-) ALCL (p=0,678) and mediastinal gray zone lymphomas (p=0,327). GATA3 expression is significantly higher in EBV (-) CHLs (p=0,02). In core needle biopsies its diagnostic performance is limited (p=0,178).

Conclusions: GATA3 is a useful marker for differentiating CHL from B-cell non-Hodgkin lymphomas but its efficiency is limited in ALK (-) ALCL and mediastinal grey zone lymphomas. Due to the heterogeneous reaction diagnostic value is limited in core needle biopsies.