Sometimes a picture is worth a thousand words – use of old‐fashioned microscopy to gain a new appreciation for the cells found in human milk

Abstract

The visualization of exfoliated human milk cells for breast cancer detection was described over 50 years ago. However, microscopic examination of these cells is now rare. We are interested in using these cells to study nutrigenomics in mammary epithelium and nutrient‐host‐pathogen interactions during breast infections. As such, we have “redeveloped” the methods required to visualize these cells and have now used these methods to visualize and characterize ~80 such samples. Milk was collected from healthy, lactating women via complete breast expression. Samples were centrifuged, the milk fat removed, supernatant aspirated, and the remaining cell pellet resuspended. After recentrifugation, the supernatant was aspirated, and the remaining cell pellet rewashed. Slides were produced with 50 μL of the resuspended cell pellet, and stained with Wright‐Giemsa. Overall, 47, 32, 15, 2, and 2% of the cells were identified as macrophage/epithelial, neutrophils, lymphocytes, eosinophils, and squamous epithelial, respectively. Subjective analysis indicates a high degree of intrasubject consistency. Interestingly, many samples were laden with neutrophils even when no signs or symptoms of breast infection were present. These observations will be systematically illustrated through a series of images. Funded by the United Dairymen of Idaho and NIH‐NRRI grant P20 RR15587.