Pregnancy and lactational changes

Most breast lesions in pregnant and postpartum women are benign and result from hormonal stimulation of breast tissue. Pregnancy can produce lactating adenomas or cause enlargement of preexisting breast lesions such as fibroadenomas.

Lactating adenoma and lactational change - cytologic diagnostic features

• Cellular smears
• Bubbly vacuolated secretions in the background
• Numerous aggregates, loose clusters, and individually dispersed cells with frayed and
  vacuolated cytoplasm
• Absence of bipolar bare nuclei (except in fibroadenomas with lactational change)
• Acinar cells with rounded nuclei, prominent nucleoli and abundant fragile vacuolated cytoplasm
• Stripped round to oval nuclei with obvious nucleoli