A Case of Benign Phyllodes Tumor in a Transgender Woman Receiving Cross-Sex Hormones.

Phyllodes tumor is a relatively uncommon fibroepithelial neoplasm of the breast characterized by proliferation of both stromal and epithelial elements. Benign phyllodes tumors are distinguished from fibroadenomas by their prominent leaf-like architecture and exaggerated intracanalicular stromal growth pattern. Typically, these lesions affect older natal females; however, we present what we believe is the first reported case of benign phyllodes tumor in a hormonally treated transgender woman.