BREAST CYTOPATHOLOGY

Lobular Carcinoma 97
• Seen in premenopausal age
• Multicentric and often bilateral
• Often associated with atypical lobular hyperplasia
• Increased risk of developing invasive carcinoma
Cytomorphologic Characteristics (Figures 4.18 and 4.19)
• Moderately cellular
• Epithelial fragments, often depicting intact lobular
structures
• Myoepithelial cell layer present around the intact neoplastic
lobules
• Small cells, tightly packed with monomorphic round nuclei,
scant cytoplasm
• Intracytoplasmic vacuoles or lumina, sometimes with targetoid
mucin vacuoles
• Because the cytopathologic features of lobular carcinoma
in situ are often shared with invasive lobular carcinoma,
Figure 4.18. Lobular carcinoma. A well-formed, cohesive fragment
of uniform hyperchromatic malignant cells. A lobular architecture
is clearly evident. A follow-up biopsy revealed lobular carcinoma in
situ. (Smear, Papanicolaou.)