Benign Melanosis of the Nipple and Areola During Pregnancy: A Case Report

Benign melanosis of the nipple and areola is a rare pigmentary disorder that may clinically mimic malignant melanoma and pigmented Paget’s disease, particularly during pregnancy. We report a 30-year-old woman at 28 weeks’ gestation who presented with bilaterally asymmetric, heterogeneously hyperpigmented macules on the nipples and areolae. Dermoscopy revealed a prominent and regular pigment network with heterogeneous light- and dark- brown coloration. Multiple punch biopsies were performed to exclude melanoma in situ. Histopathological examination showed irregular acanthosis and increased basal layer pigmentation without melanocytic atypia. Immunohistochemical staining demonstrated scattered MART-1– and HMB-45–positive melanocytes without an increase in number, supporting the diagnosis of benign melanosis of the nipple and areola. The coexistence of vitiligo represents a rare and noteworthy feature of this case. This report emphasizes the importance of histopathological evaluation in differentiating benign melanosis from malignant pigmented lesions in pregnant patients.