BREAST CYTOPATHOLOGY

• They typically present as a solid or partially cystic nodule
with a slight predilection for females of middle age.
Cytomorphologic Characteristics (Figures 4.49 and 4.50)
• Will depend on the type of sweat gland tumor. They may
appear deceptively bland, basaloid, squamous, or mucinous.
Accurate distinction from a primary ductal neoplasm
could be extremely difficult on a limited FNA sample, particularly
when a good clinical history and physical findings
are not available at the time of FNA interpretation.
Pitfalls and Differential Diagnosis
• Primary breast carcinoma
• Metastatic carcinomas
Special Types of Breast Carcinomas 131
Figure 4.49. Sweat gland tumor (malignant nodular hidradenoma).
A large epithelial fragment composed of round, uniform nuclei. A
distinction from atypical ductal hyperplasia or well-differentiated
ductal carcinoma can be difficult. However, note the absence
of any single epithelial cells in the background. (Smear,
Papanicolaou.)