Immunohistochemical GATA3 expression in prostate adenocarcinoma: pitfalls

Recent studies have reported aberrant GATA3 immunohistochemical expression in high-grade prostate carcinoma, raising concerns about its specificity. This study aimed to evaluate GATA3 immunohistochemical expression in prostate adenocarcinoma. We retrospectively collected cases of primary prostate adenocarcinoma diagnosed in our pathology department(2019-2024). Clinical and pathological data, including Gleason and ISUP grades, were collected.An automated immunohistochemical analysis was performed using the anti-GATA3 antibody(Leica, L50-823). Only nuclear staining was considered positive. Fifty-eight cases have been included in the study with a mean age of 67.8 years-old. GATA3 nuclear expression was observed in 6.9% (4/58) of cases, all classified as Gleason 7 (4 + 3) and ISUP grade 3. Only the Gleason 4 or 5 components showed staining, while Gleason 3 components were negative. Additionally, benign prostate glands and seminal vesicles showed rare GATA3 expression (4/58 and 1/58 cases, respectively). While GATA3 is commonly used as a marker for urothelial carcinoma, our findings indicate that it can also be expressed in prostate adenocarcinoma, particularly in higher Gleason grade components, which may pose a diagnostic pitfall. Further studies are needed to determine the clinical significance of GATA3 expression in prostate adenocarcinoma and its potential impact on tumor behavior and prognosis.