Apocrine change in fine-needle aspiration biopsy: nuclear morphometry and DNA image cytometry

The aim of this study was to investigate the potential of computerized nuclear morphometry and DNA image cytometry in characterizing the apocrine change of mammary epithelium in fine-needle aspiration biopsy (FNAB). The effect of two different sample processing techniques on the results was also studied. Mean nuclear areas in air-dried smears ranged from 59.0 microm2 to 151.0 microm2 and in ethanol-fixed samples from 32.3 microm2 to 63.4 microm2. The DNA histograms of apocrine cells usually showed a dominant peak in the diploid region. In some cases the mode of the peak was slightly shifted to the right or left in respect to the control peak. One case had a tetraploid cell population, suggesting atypical apocrine change. After histological investigation this case was diagnosed as infiltrating carcinoma. The patient had earlier been treated with x-ray irradiation for a mediastinal lymphoma. Findings of nuclear morphometry and DNA cytometry in apocrine metaplasia are here described in a systematic study for the first time. The data suggest that these methods may help in distinguishing premalignant and malignant apocrine lesions from typical apocrine metaplasia of mammary epithelial cells.