Dermatology: Practical and Conceptual Image Letter | Dermatol Pract Concept. 2023;13(1):e2023040 1 Dermoscopic Features of Pigmented Mammary Paget Disease Arturo Robles-Tenorio1, Adriana Rendon2 1 School of Medicine and Health Sciences, Tecnologico de Monterrey, Nuevo Leon, Mexico 2 Dermatology Department, Heidelberg University Clinic, Heidelberg, Germany Citation: Robles-Tenorio A, Rendon A. Dermoscopic Features of Pigmented Mammary Paget Disease. Dermatol Pract Concept. 2023;13(1):e2023040. DOI: https://doi.org/10.5826/dpc.1301a40 Accepted: May 11, 2022; Published: January 2023 Copyright: ©2023 Robles-Tenorio et al. This is an open-access article distributed under the terms of the Creative Commons Attribution- NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original authors and source are credited. Funding: None. Competing Interests: None. Authorship: All authors have contributed significantly to this publication. Corresponding Author: Adriana Rendon, Dermatology Department, Heidelberg University Clinic, Im Neuenheimer Feld 440, Heidelberg, Germany 69120, +49 06221-5634296, E-mail: adriana.rendon@med.uni-heidelberg.de Case Presentation A 69-year-old, Hispanic woman presented with a 6-month history of an irregular, asymmetrical, dark brown lesion on the left nipple, surrounded by a discrete pink plaque (Figure 1A). Dermoscopic examination showed an atypical pigment net- work, black granules and globules at the center of the lesion, as well as structureless pink and white areas (Figure  1B). Histopathology revealed epidermal infiltration by large, atypical, pale cells. Immunohistochemistry was negative for negative for s100, Melan-A, and HMB-45, hence ruling out the presumptive diagnosis of malignant melanoma. Immu- nohistochemical staining for CK7 and GATA3 was positive and therefore, pigmented mammary Paget disease was di- agnosed. The patient was referred to the surgical oncology team and underwent modified radical mastectomy. No evi- dence of lymph node invasion was detected. At the 6-month follow up, the patient remains free of recurrence. Teaching Point Pigmented mammary Paget disease (PMPD) is a rare pre- sentation of a breast intraductal carcinoma that extends to the epidermis of the nipple-areola complex [1]. The main differential diagnoses include malignant melanoma and pigmented epidermotropic metastases of breast car- cinoma. PMPD dermoscopy findings include atypical pigment network, structureless blue-grey areas, brown or blue dots and globules, as well as other non-pigmented findings (structureless pink and/or white areas) [2]. His- topathology and immunohistochemistry are essential for the diagnosis. Particularly in skin of color patients, further dermoscopic descriptions are warranted, as even benign lesions (lentigo, nipple-areola melanosis, naevi, seborrheic keratosis) can resemble PMPD. Therefore, new-onset, evolving, pigmented lesions in the nipple-areola complex should be biopsied. 2 Image Letter | Dermatol Pract Concept. 2023;13(1):e2023040 References 1. Requena L, Sangueza M, Sangueza OP, Kutzner H. Pigmented mammary Paget disease and pigmented epidermotropic metastases from breast carcinoma. Am J Dermatopathol. 2002;24(3):189-198. DOI: 10.1097/00000372-200206000-00001. PMID: 12140433. Figure 1. Pigmented mammary Paget disease. (A) Clinical inspection revealed a heterogeneously pigmented, irregular lesion affecting the left nipple, surrounded by a discrete pink plaque. (B) Dermoscopy findings included an atypical pigment network admixed with structureless pink and white areas, as well as black granules/globules towards the center of the lesion. 2. Apalla Z, Errichetti E, Kyrgidis A, et al. Dermoscopic features of mammary Paget’s disease: a retrospective case‐control study by the International Dermoscopy Society. J Eur Acad Derma- tol Venereol. 2019;33(10):1892-1898. DOI: 10.1111/jdv.15732. PMID: 31270878.