Mammary Paget's disease with acantholytic features and without any detectable breast tumor.

Abstract Paget's disease is usually associated with an underlying adenocarcinoma of the breast. The initial manifestation is an eczematous or psoriasiform lesion of the nipple, soon extending to the mammary areola and then to the surrounding skin. The histology of the lesions is characterized by the presence, within the epidermal layer, of the so-called Paget's cells, i.e. large cells with vesicular nucleus and clear cytoplasm. The authors report a recent case of Paget's disease of the breast in a 75-year-old woman, unusual both for clinical course and observed histology. As for the clinico-evolutive aspects, although in the case observed the initial skin lesions appeared 20 years before, the different diagnostic procedures repeatedly performed showed no evidence in this patient of an underlying adenocarcinoma. The histologic aspect, on the other hand, was peculiar since the typical characteristics of an acantholytic disease were evident. The presence of intraepidermal cleavages with lost, at times, of the normal contacts among the cells of the Malpighian layer has been described only once in Paget's disease. This fact caused some diagnostic difficulties: however, the typical finding of the Paget cells, their positivity to histochemical methods such as cytokeratin and acid phosphatase allowed the diagnosis. The authors, at last, evaluate the need of a surgical therapy in Paget's disease of the breast without an underlying adenocarcinoma.