Abstract: | Thin needle aspirates of 42 consecutive breast carcinomas were obtained at the time of excisional biopsy. Nuclear diameters of 100 cells from each case were measured, and the nuclear areas were calculated. The concomitantly acquired histologic sections were reviewed and assigned a histologic grade according to the National Surgical Adjuvant Breast Project protocol no. 4. Estrogen receptor (ER) content was analyzed by both the DCCA and SDGA techniques. The ER content of each case was then compared to both the mean nuclear area of the cells on the cytologic smears and the histologic grade. All 16 cases with mean nuclear areas of less than 60 sq micrometer contained significant levels of ER (greater than 10 fmol/mg protein), as did 6 of 11 cases with nuclei between 60 and 90 sq micrometer. Only 5 of 15 cases with nuclei larger than 90 sq micrometer contained significant ER levels. Comparison of the sensitivity, specificity and predictive values of both techniques suggests that a quantitative assessment of nuclear area in cytologic thin needle aspirates correlates more closely with ER content than does histologic grading. |