Dermatology Online Journal

We report a case of a woman who presented with a cystic-appearing nodule on her left nipple. After cutaneous biopsy and gynecological staging study, she was diagnosed with skin invasion of mucinous carcinoma of the breast. We describe the main features of this rare tumor and the controversies in its diagnosis because primary and metastatic mucinous carcinomas in skin are histologically indistinguishable.