A Primer on Extramammary Paget's Disease for the Urologist

Joon Yau Leong; Paul H. Chung


Transl Androl Urol. 2020;9(1):93-105. 

In This Article

Epidemiology & Pathophysiology

The incidence of EMPD has been reported to be as low as 0.12 per 100,000 people and represents 21% of primary scrotal cancers and 2% of primary vulvar cancers, respectively.[5–7] With regards to gender and racial preponderance, Asian men seem to have a fourfold increased risk of being diagnosed with EMPD when compared to their Caucasian counterparts.[1,8] Previous studies have also reported a female predominance in Caucasian populations (M:F ratio of 1:2–1:7) with the opposite being true among the Asian population (M:F ratio of 2:1–4:1).[5] EMPD represents 6.5% of all cutaneous Paget's disease and it predominantly affects patients between ages 50 to 80 years, with a peak age of 66 years old.[9–11] The most common sites affected by EMPD is the vulva (65%), followed by the perianal region (20%) and subsequently the penoscrotal and groin areas (14%).[12]

Two prognostically distinct pathogenesis of EMPD have been described.[13] In the primary or intraepidermal form, carcinoma develops in situ from the apocrine gland ducts and is less commonly associated with an underlying malignancy; however, it is still capable of invading the dermal layers and metastasizing over time.[14] In contrast, the secondary form arises from an epidermotropic spread of malignant cells from a primary tumor within a contiguous epithelium, such as the genitourinary or gastrointestinal tract, or from a dermal adnexal gland.[15,16]