Melanin Pigment Uptake Within Paget Cells

Abstract

Background: The differential diagnosis of intraepidermal neoplasms showing cell clusters and/or single units with upward migration includes Pagets disease, melanoma in‐situ, Bowens disease, and Pagetoid reticulosis. Purpose: We describe three cases of Pagets disease of the nipple with melanin pigment uptake by Paget cells. Results: Clinical and pathologic material of three women with biopsy proven Pagets disease of the nipple was reviewed. Clinically, two cases demonstrated an excoriated nipple, one of which also showed a zone of depigmentation. The clinical appearance of the third case was not available. Histologically, each case demonstrated Paget cells singly and in clusters with cytoplasmic uptake of melanin pigment. Melanocytes were found in each case, but were neither increased in number nor showed atypical forms. The dendritic processes of melanocytes were found to encase single Paget cells. Pigment was also found dispersed in the papillary dermis and within melanophages. Conclusions: Melanin pigment uptake by Paget cells represents a significant potential pitfall in ultimately arriving at the correct diagnosis. Misdiagnosing these cases as a melanocytic lesion could potentially delay the management of an underlying breast cancer. Careful examination of melanocyte and melanin distribution with respect to Paget cells is warranted in such cases.