Fractal dimensions of breast lesions on cytology smears

In the present study, box-counting fractal dimensions of benign and malignant cells of breast tumors on cytology material were measured and compared. We selected fine-needle aspiration cytology smears of 14 cases of histopathology-proven infiltrating duct carcinomas and 7 cases of fibroadenoma of the breast. Five cells were randomly selected from each case. Box-counting fractal dimensions of all cells were measured with the help of an image cytometer (Leica, Cambridge, UK), using Quantimet 600 software (Leica). In total, 70 malignant cells and 35 benign cells were studied. The mean fractal dimensions of malignant cells and benign cells were 0.9571 +/- 0.1265 and 0.8354 +/- 0.1367, respectively. There was significant difference in the fractal dimension of malignant and benign cells (P = 0.006, Mann-Whitney nonparametric test). The measurement of fractal dimension may be helpful in discriminating malignant from benign cells. This may be another discriminating feature of malignant cells, along with classic image morphometry based on Euclidean geometry.