GATA3 and TRPS1 Expression in Follicular Dendritic Cell Sarcoma.

Follicular dendritic cell sarcoma (FDCS), a rare soft tissue sarcoma, has a broad anatomic distribution and a wide histological spectrum. It may exhibit epithelioid features. When it occurs in patients with concurrent breast carcinoma, it may be misdiagnosed as metastatic breast carcinoma. In the current study, we investigated the expression of GATA3 and TRPS1, 2 commonly used breast markers, in 15 FDCS tumors diagnosed between 2015 and 2024 to evaluate their utility in differentiating FDCS from breast carcinomas. Low to strong positive GATA3 expression was detected in 6 FDCS tumors, whereas none expressed TRPS1. Therefore, the presence of relatively strong GATA3 expression is not necessarily associated with breast carcinoma or sufficient to rule out the possibility of FDCS, especially in the context of breast and axillary tumors. TRPS1 may be a helpful marker for distinguishing FDCS from breast carcinoma.