Pigmented Extramammary Paget’s Disease of the Axilla Mimicking Melanoma

What is it about?

Pigmented extramammary Paget’s disease (EMPD) is a rare variant which is often confused clinically and histologically with melanoma or other pigmented lesions. Herein, we describe a rare case of pigmented EMPD involving the axilla of a 40-year-old female thought initially to represent malignant melanoma clinically. Immunohistochemically, the neoplastic cells are positive for Estrogen Receptor (ER) and progesterone Receptor (PR), and weakly positive for Human Epidermal Growth Factor Receptor 2 (Her2).

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Photo by Ana Essentiels on Unsplash

Photo by Ana Essentiels on Unsplash

Why is it important?

A review of the literature reveals that the pigmented variant of EMPD could be easily misdiagnosed as melanoma initially and additional confirmatory studies are almost always needed to confirm the diagnosis. The expression of ER and PR in pigmented EMPD is rarely mentioned previously. We believe it should be further investigated for the understanding of pathogenesis in pigmented EMPD and the potential role of adjuvant hormonal therapy.