Background
Fine needle aspiration (FNA) of breast masses in pregnant or lactating women is an uncommon procedure, and cytological interpretation is considered problematic due to atypia inherent to secretory change in glandular epithelia. Previous descriptions of “lactating adenoma” (LAd), the most common tumor in this population, have been on direct smears (DS), while ThinPrep (TP, Hologic, Boxborough, MA) findings therein remain largely uncharacterized.
Methods
FNA cases from breast masses in pregnant or lactating women (2005–2012), processed as TP and/or DS were retrospectively reviewed.
Results
28 cases from as many patients (mean age 36 years), at 23 weeks of pregnancy to 10 months postpartum, were reviewed. Size of mass ranged from 1.0 to 4.5 cm. Corresponding histopathology was available in 21/28 cases. TP was available in 24/28 cases. Relative to DS, in TP, LAd showed “lacy” fragments, tissue paper‐like texture, and globular clumps of “milky” background material, with embedded singly dispersed “bare” epithelial cell nuclei containing cherry‐red macronucleoli. Architecture appeared disrupted in TP with isolated cells, smaller cell clusters, and lobules in LAd. Cellular morphology was better preserved in TP. Cytological features of carcinoma on TP were similar to DS. There were no false‐positive cases. In this series, LAd was the most common diagnosis for breast masses in pregnant and lactating women (78.5%) and demonstrated background, architectural, and cellular alterations on TP.
Conclusion
In this setting, malignancy is an important consideration (encountered in 3/28, 11% of cases, including one false‐negative angiosarcoma case). Diagn. Cytopathol. 2015;43:188–194. © 2014 Wiley Periodicals, Inc.