Figure 4From: Columnar cell lesions of the canine mammary gland: pathological features and immunophenotypic analysis Canine mammary biopsies with immunohistochemical staining of columnar cell lesion (CCL). Columnar cell change without atypia showing intense immunostaining for estrogen receptor (4A) and progesterone receptor (4B). Flat epithelial atypia with moderate membrane E-cadherin reactivity (4C) and nuclear expression for Ki-67 (4D), 600×.Back to article page