Intermediate magnification micrograph showing the relative abundance of<unk> in a case of<unk> . H&E stain. The diagnosis of<unk>  is by biopsy. The important differential diagnosis is angiosarcoma, from which it was first differentiated in 1986. Differential diagnosis *Fibroadenoma *Angiosarcoma
Pseudoangiomatous stromal hyperplasia
Germ cell neoplasia in situ
Surface epithelial-stromal tumor
Leiomyomatous hamartoma
Microglandular hyperplasia
Epithelial dysplasia
In situ lymphoid neoplasia
Mesothelial hyperplasia