NR4A3 (NOR-1) Immunostaining Shows Better Performance than DOG1 Immunostaining in Acinic Cell Carcinoma of Salivary Gland: a Preliminary Study

Objectives Acinic cell carcinoma of salivary gland harbours recurrent and specific chromosomal rearrangement [t(4;9)(q13;q31)], resulting in the translocation of secretory calcium-binding phosphoprotein gene cluster at 4q13 to nuclear receptor subfamily 4 group a member 3 at 9q31. This upregulates the transcription factor nuclear receptor subfamily 4 group A member 3, which can be detected by immunohistochemistry. The purpose of this pilot study is to evaluate the performance of nuclear receptor subfamily 4 group A member 3 immunostaining on whole-slide acinic cell carcinoma tissue, in comparison with discovered on GIST-1 immunostaining. Material and Methods We retrieved 6 cases of acinic cell carcinoma (AciCC), including 5 conventional low-grade and 1 dedifferentiated high-grade. Immunohistochemistry (IHC) for nuclear receptor subfamily 4 group A member 3 (NR4A3) and discovered on GIST-1 (DOG1) were performed at the University of Pittsburgh Medical Centre in Pittsburgh, Pennsylvania on all retrieved cases. Results The result shows that NR4A3 IHC shows better performance than DOG1 IHC: 5 of the 6 (83.3%) AciCC cases (including the dedifferentiated high-grade) demonstrated strong diffuse nuclear staining for NR4A3, also five AciCC cases (including the dedifferentiated high-grade) demonstrated weak to moderate membranous staining with variable distribution for DOG1. Moreover, only 3 (50%) cases showed complete membranous staining with DOG1. Conclusions This pilot study showed that nuclear receptor subfamily 4 group A member 3 immunostaining is a sensitive marker for acinic cell carcinoma and of better utility than discovered on GIST-1 immunostaining in making a diagnosis of acinic cell carcinoma.