Authors analyzed 143 cases of breast Paget disease with special emphasis on basic tumor process and on immune histochemical characteristics of tumor cells. Breast Paget disease represent special clinical presentation of the breast tumor. The most often tumor in the breast are ductal carcinoma in situ, ductal carcinoma and in rare instance lobular carcinoma and lobular carcinoma in situ. There are several clinical combinations with or without involvement of axillary's lymph nodes. The best prognosis is in cases with in situ as underlying process. All other combinations have worse prognosis in relation to the combination with in situ lesion. The middle ages of patients with Paget disease is 10 years higher than the ages without areola involvement. Paget cells show the same immune histochemical characteristic as tumor cells. The authors propose mastectomy instead central segmentectomy.