1. A method for detecting cancerous or other types of abnormal cells in a blood sample, comprising: (a) staining the nuclei of cells in the blood sample using a nuclear dye or stain, producing stained cells; (b) removing red blood cells from the blood sample, leaving a residual sample comprising primarily white blood cells and a fluid; (c) imaging the stained cells to simultaneously produce a plurality of different types of images of each stained cell; (d) automatically evaluating the plurality of different types of images to detect features of the images, and based on classifiers previously defined as a function of features selected for distinguishing each of a plurality of different types of white blood cells, automatically identifying a first subset of the stained cells as specific types of white blood cells in the blood sample, where a second subset of cells includes cells that were not identified as being any type of white blood cell; and (e) manually reviewing images of the second subset of cells to determine whether any of the cells in the second subset are cancerous or other type of abnormal cell.