BREAST CYTOPATHOLOGY

Figure 3.5. Fibroadenoma. This branching tubular structure can be
confused with a well-differentiated tubular carcinoma. However, the
presence of numerous background myoepithelial nuclei is extremely
helpful to exclude malignancies. (Smear, Papanicolaou.)
Figure 3.6. Fibroadenoma. A higher magnification shows cytologic
atypia of the ductal epithelium with enlarged nuclei and occasional
prominent nucleoli. Numerous myoepithelial cell nuclei are present
in the background. The diagnosis of fibroadenoma is typically rendered
on an appreciation of the cellular architecture at lower magnifications.
A significant degree of cytologic atypia is often present
in these tumors and can lead to diagnostic confusion when an aspirate
of fibroadenoma is evaluated at higher magnifications. (Smear,
Papanicolaou.)