ESPE Abstracts

Background: Testicular Adrenal Rest Tumours (TARTs) are benign tumours that frequently occur in male patients with congenital adrenal hyperplasia. They exhibit both testicular and adrenal characteristics, but their aetiology is unknown. Additionally, TART resembles Leydig cell tumours (LCTs), while no marker exist to discriminate between these testis tumours. GATA transcription factors play an important role in eukaryotic development and are expressed in foetal and adult adrenal gland and gonads.

Objective and hypotheses: To determine if GATA transcription factors can discriminate between TART, testis and LCT.

Method: Gene expression analysis was performed for GATA 1, 3, 4, and 6 in TART (n=12), adult testis tissue (n=8), and adult adrenal tissue (n=12). Expression levels were compared and tested with Kruskal-Wallis-test followed by Dunns test (P<0.05). Receiver operating characteristic (ROC) curve was used to determine discriminative properties. Protein expression in TART (n=16) and LCTs with accompanied normal testis tissue (n=7) was tested using immunohistochemistry (IHC).

Results: GATA4 gene expression was significantly higher in TART compared to adrenal (P<0.001), while gene expression of GATA3 and GATA6 were significantly higher in TART compared to testis (both P<0.05), with ROC areas under the curve of 0.979 and 0.906, respectively. GATA3 protein expression was undetectable in TART as well as LCT. In both TART as well as LCT, GATA6 showed nuclear or cytoplasmic staining patterns, ranging from weak to strong staining intensity.

Conclusion: Our study shows that both GATA3 and GATA6 mRNA expression is higher in TART compared to adult testis tissue with good discriminative potential between TART and testis. However, GATA3 and GATA6 protein expression could not discriminate between TART and LCT.