GATA3 Immunoexpression in Salivary Gland Neoplasms
Lauren E Schwartz, William H Westra, Justin A Bishop. Johns Hopkins Hospital, Baltimore, MD
Background: GATA3 is a zinc finger transcription factor that regulates the normal development of many tissues and cell types. Recent studies have shown that immunohistochemical nuclear staining for GATA3 among tumors is almost entirely limited to carcinomas of breast and urothelial origin. However, to our knowledge salivary gland tumors have not been tested with this antibody. Given that breast tissue and salivary gland tissue share a similar embryologic origin, we sought to determine whether GATA3 staining may be seen in salivary gland neoplasms.
Design: GATA3 immunohistochemistry (clone L50-823, BioCare, Concord, CA) was performed on a diverse collection of 164 primary salivary gland neoplasms (122 on tissue microarrays and 42 on whole slides), and the staining patterns were recorded.
Results: The results are summarized in Table 1. Staining for GATA3 was observed in 81/164 (49%) of salivary gland tumors. The background benign salivary was also usually weakly positive in acini and ducts. Some staining was seen in almost every tumor type tested, but it was particularly common in tumors with an "oncocytic" histologic appearance. Notably, GATA3 was 100% sensitive for two tumors that histologically mimic breast cancer: salivary duct carcinoma (25/25) and mammary analogue secretory carcinoma (15/15). Overall, most GATA3 tumor staining was weak or moderate in intensity, though salivary duct carcinoma (17/25 or 68%) and mammary analogue secretory carcinoma (9/15 or 60%) often showed strong positivity.
|Tumor type||GATA3 staining (%)|
|Acinic cell carcinoma||1/7 (14)|
|Adenocarcinoma, NOS||0/2 (0)|
|Adenoid cystic carcinoma||9/41 (22)|
|Epithelial-myoepithelial carcinoma||1/2 (50)|
|Mammary analogue secretory carcinoma||15/15 (100)|
|Mucoepidermoid carcinoma||11/27 (41)|
|Oncocytic carcinoma||1/2 (50)|
|Pleomorphic adenoma||13/34 (38)|
|Polymorphous low grade adenocarcinoma||0/4 (0)|
|Salivary duct carcinoma||25/25 (100)|