Figure 1.
A 63-year-old woman with a breast tumor. A, Low-power magnification showing well-circumscribed borders. B, The tumor cells are highly atypical and mixed with lymphocytes and plasma cells. C, There is focal infiltration into the fat. D through F, Immunohistochemical stains for estrogen receptor (ER), progesterone receptor (PR), and HER2/neu are negative, respectively (hematoxylin-eosin, original magnifications ×2 [A], ×40 [B], ×20 [C]; immunostains for ER [D], PR [E], and HER2/neu [F], original magnifications ×40).