Chapter 106: Paget’s and Extramammary Paget’s Disease

PAGET’S AND EXTRAMAMMARY PAGET’S DISEASE

Therapeutic Approach

Mammary Paget’s disease (MPD) and extramammary Paget’s disease (EMPD) are rare intraepithelial carcinomas.^1-2 MPD is typically associated with underlying breast cancer and most commonly affects postmenopausal women.¹ It is characterized by erythematous, eczematous, weeping or crusted plaques on the nipple and periareolar skin.¹ In contrast, EMPD typically occurs in sites with a high concentration of apocrine glands, including the genital skin, axillae, and anus, with the vulva being the most frequently affected region.² EMPD is seen most commonly in older Caucasian females and Asian males and typically occurs in the 6th to 8th decades of life.² It can arise as a primary cutaneous adenocarcinoma or may be secondary to an underlying adenocarcinoma.² Both MPD and EMPD can mimic inflammatory skin disorders and therapy is often delayed due a prolonged time to definitive diagnosis.^1,2 The treatment of EMPD is based on the degree of extension and underlying malignancy. Treatments for localized disease include surgical resection, including Mohs micrographic surgery (first-line) and wide local excision (second-line), topical chemotherapy (reserved for poor surgical candidates), photodynamic therapy, and radiotherapy; however, recurrence rates can be high. Invasive disease, lymphovascular invasion, lymph node metastasis, and positive resection margins portend a worse prognosis.² Management of MPD varies based upon the clinical and histologic features of the underlying breast cancer and will not be addressed in this chapter. See Table 106-1.