When Sir James Paget wrote, in 1874, his classical account of the disease which bears his name, he described the condition clinically, rather than pathologically. Based on his own observation of fifteen cases, he outlined the course of a moist, red eczema followed by ulceration of the nipple and areola, upon which cancer of the underlying breast constantly developed. In each of his fifteen cases the breast cancer made its appearance within a year, or at most two years, after the onset of the nipple eczema.
The fact that Paget's description did not include that of the histopathology of the disease has been responsible for much of the confusion which has existed, and still exists, in the minds of surgeons and pathologists over the exact nature of Paget's disease. Without the evidence of microscopic study, it is impossible, many times, to distinguish between true Paget's disease and secondary ulceration of
KILGORE AR. IS PAGET'S DISEASE OF THE NIPPLE PRIMARY OR SECONDARY TO CANCER OF THE UNDERLYING BREAST?. Arch Surg. 1921;3(2):324-335. doi:10.1001/archsurg.1921.01110080082002