BREAST CYTOPATHOLOGY

6
Breast Ductal Lavage
To obtain nipple aspiration fluid (NAF), a pump and/or a
syringe connected to a suction cup is applied to the nipple
and the aspirated fluid is collected using a capillary tube. This
procedure yields NAF in 59%–99% of women. A volume of
20–30μl of fluid can be obtained (range 1–200). About 77%
of the cells of NAF are foam cells of macrophage derivation,
and only 13% are ductal epithelial cells (median 120 cells/
duct). Criteria for evaluation of NAF were developed in the
mid-1970s and are similar to the criteria used for evaluation
of breast FNA material. The cytologic findings in NAF from
2,701 volunteer women with no family history of breast cancer
and no breast carcinoma at the time of enrollment were analyzed
prospectively. The overall incidence of breast cancer in
this cohort was 4.4% after median follow-up of 12.7 years. In
this study, both incidence and relative risk of breast cancer
increased with increasing severity of cytologic diagnosis of
the NAF (Table 6.1). Although the relative risk of breast
cancer associated with abnormal NAF was reduced in an
updated analysis of the data, these results have generated
much interest in the use of mammary cytology for the evaluation
of breast cancer risk.
Some investigators have detected in NAF factors
associated with mammary neoplasia; others have performed
proteomic analysis and molecular evaluation of NAF,
but there is no clinical application for these findings at
present.
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