Extramammary Paget's disease

Extramammary Paget's disease (EMPD) is a rare and slow-growing cancer, which occurs within the epithelial tissues and accounts for 6.5% of all Paget's disease. This disease presents similarly to the more conventional form of mammary Paget's disease (MPD). However, unlike MPD, which occurs in large milk-carrying ducts in the breast and then extends into the epidermis, EMPD begins in glandular regions rich in apocrine secretions outside the mammary glands. EMPD incidence is increasing by 3.2% every year, affecting hormonally-targeted tissues such as the vulva and scrotum. In women, 81.3% of EMPD cases are related to the vulva, while for men, 43.2% of the manifestations present at the scrotum.

The disease can be classified as being either primary or secondary depending on the presence or absence of associated malignancies. EMPD presents with typical symptoms such as scaly, erythematous, eczematous lesions accompanied by itchiness. In addition to this, 10% of patients are often asymptomatic. As a consequence, EMPD has high rates of misdiagnoses and delayed diagnoses. There are a variety of treatment options available, but most are unsuccessful. If caught early and treated, prognosis is generally good.