BREAST CYTOPATHOLOGY

86 4. Primary Malignant Tumors
• Myoepithelial cells are lacking.
• The cribriform type is characterized by cohesive sheetlike
fragments of bland cells with sharply punched out holes.
The micropapillary form is characterized by abundant large
cellular fragments with slender, well-formed papillary
structures with narrow avascular stalks and wide bulbous
ends. The comedo type is characterized by degenerated/
necrotic cellular debris, microcalcifications, foamy macrophages,
and pleomorphic malignant cells with a high nuclear
grade. The cystic hypersecretory type is characterized by
pleomorphic cells with cytoplasmic vacuoles and often
hobnailed nuclei associated with foamy macrophages,
hemosiderin-laden macrophages, cellular debris, and fragments
of amorphous colloid-like material.
• A cytopathologic distinction between ductal carcinoma
in situ and invasive ductal carcinoma is not possible in
most of the cases. Therefore, traditionally both forms of
cancers are grouped under the broad cytologic category of
“mammary carcinoma.”
Figure 4.1. Ductal carcinoma. Pleomorphic, hyperchromatic malignant
cells are seen in a disorganized architecture. A few single
malignant cells are present as well. Follow-up biopsy revealed ductal
carcinoma in situ, comedo type. (Smear, Papanicolaou.)