Table 1 Histologic features of the different categories of columnar cell lesions in canine mammary gland.
Columnar Cell Change without atypia (CCC) | Columnar Cell Hyperplasia (CCH) | Flat Epithelial Atypia (FEA) | Flat Epithelial Atypia (FEA) |
|---|---|---|---|
CCC with atypia | CCH with atypia | ||
One to two columnar cell layers with uniform ovoid to elongated nuclei; nucleoli absent or inconspicuous. | Cellular stratification more than two columnar cell layers with uniform ovoid to elongated nuclei; nucleoli absent or inconspicuous. | One to two columnar cell layers with complex architectural patterns present; Mild to moderate cytologic atypia present (usually low-grade): round-to- ovoid, mildly pleomorphic and hyperchromatic nuclei, with inconspicuous nucleoli. | Cellular stratification more than two columnar cell layers with complex architectural patterns present; Mild to moderate cytologic atypia present (usually low-grade): round-to- ovoid, mildly pleomorphic and hyperchromatic nuclei, with inconspicuous nucleoli. |