Fig. 5
From: Granulocyte-colony stimulating factor-producing malignant phyllodes tumor of the breast: a rare case
Histologic examination of the excised tumor. a H&E stain reveals many poorly differentiated and highly atypical cells. Tumors mainly consist of spindle-shaped to polygonal atypical high-grade stromal cells that grow into sheets while forming multinucleated giant cells. b Immunostaining of the tumor cells is positive for G-CSF