BREAST CYTOPATHOLOGY

92 4. Primary Malignant Tumors
Histologic Features
Histologically, infiltrating duct cell carcinoma is characterized
by a spectrum of changes that vary according to the atypia
and differentiation, such as the degree of tubule formation,
nuclear pleomorphism, and mitotic activity. Cytologically,
variable patterns reflecting the diverse histologic morphology
of the tumors are seen. Breast aspirates of infiltrating duct
cell carcinoma are cellular and often show conspicuous loss
of cell cohesion.
Cytomorphologic Characteristics (Figures 4.10 to 4.17)
• Variably cellular
• Fragments and singly dispersed malignant cells
• Often a prominent plasmacytoid cellular appearance
• Occasionally, pleomorphism, hyperchromasia, mitosis,
necrosis, and a background of tumor diathesis
Figure 4.10. Ductal carcinoma. Irregular fragments of carcinoma
with enlarged, hyperchromatic nuclei. A few single malignant cells
are noted as well. A follow-up biopsy revealed an infiltrating ductal
carcinoma. (Smear, Diff-Quik.)