BREAST CYTOPATHOLOGY

68 3. Benign and Borderline Tumors
• Less often visualized on routine mammograms as
a small mass or a dilated duct; occasionally have
microcalcifications
• Mostly in older women; may be seen in young children
or men
• Multiple papillomas often associated with concurrent
atypical duct hyperplasia or ductal carcinoma in situ
• Uneventful outcome in most cases, with only 6%
recurrence rate following excision (Approximately 6% of
the patients develop carcinomas, with majority of them
having invasive disease.)
Cytomorphologic Characteristics
(Figures 3.14 to 3.21)
• Hypercellular smears
• Large cohesive epithelial fragments, with or without threedimensional
papillary architecture and fibrovascular cores;
fragments often have scalloped edges
• Often, smaller papillary fragments with intact tips (“anatomic
edges”)
• Short or tall columnar epithelium, often palisading at the
edges of the papilla; nuclear stratification
• Background blood, hemosiderin-laden macrophages
• Significant epithelial atypia (pleomorphism, macronucleoli)
may be present
Pitfalls and Differential Diagnosis
• Papillomas may have significant epithelial proliferation,
often with focal cytologic atypia. Careful evaluation with a
much higher threshold for carcinoma diagnosis is prudent.
This is significantly important in the presence of meta -
plastic changes or in infarcted papillomas that can harbor
significant cytologic atypia (see Figure 3.21).
• Fibroadenoma
• Papillary carcinoma (in situ and invasive)