Mammary Paget's disease occurring after mastectomy

BACKGROUND: Mammary Paget's disease and extramammary Paget's disease are neoplastic conditions, in which there is intraepithelial (usually intraepidermal) infiltration by neoplastic cells showing glandular differentiation. Mammary Paget's disease occurs exclusively on the nipple/areola complex from where it may spread to the surrounding skin. CASE PRESENTATION: We here describe a case of Paget's disease occurring on the thoracic wall site of a previous simple mastectomy, and also briefly summarise the most important aspects leading to a diagnosis of mammary Paget's disease. CONCLUSION: To the best of our knowledge, this is the first reported case of mammary Paget's disease occurring after mastectomy. The absence of the nipple/areola complex obviously raised some questions concerning whether it was mammary or extra-mammary Paget's disease, and how it could occur in the absence of the nipple/areola complex.