Extramammary Paget disease

Extramammary Paget disease (EMPD) is a rare cutaneous adenocarcinoma that arises in skin areas rich in apocrine glands, outside the breast. The most commonly affected sites include the vulva, perianal region, perineum, scrotum, penis, groin, and axillae. EMPD is characterized by the presence of Paget cells — large, pale, mucin-containing neoplastic cells — within the epidermis. The condition predominantly affects older adults, typically presenting after the age of 50, and is more common in women (particularly vulvar EMPD) and in individuals of Asian descent. The hallmark symptom of EMPD is a chronic, slowly expanding, erythematous or eczematous plaque that may be pruritic (itchy), painful, or associated with a burning sensation. The affected skin may appear red, scaly, crusted, or weeping, and is frequently misdiagnosed as eczema, dermatitis, or fungal infection, leading to significant diagnostic delays. In the majority of cases, EMPD remains confined to the epidermis (in situ disease) and carries a favorable prognosis. However, in approximately 10–25% of cases, the disease may be associated with an underlying invasive adenocarcinoma or an internal malignancy of the genitourinary or gastrointestinal tract, which significantly worsens the prognosis. Treatment of EMPD depends on the extent and depth of disease. Surgical excision, including wide local excision or Mohs micrographic surgery, remains the primary treatment and offers the best chance of cure for localized disease. However, recurrence rates are notably high (up to 30–60%) due to the difficulty in achieving clear surgical margins, as the disease often extends beyond clinically visible borders. For patients who are not surgical candidates or who have recurrent disease, alternative treatments include topical imiquimod, photodynamic therapy, radiotherapy, and laser ablation. For invasive or metastatic EMPD, systemic chemotherapy or targeted therapies may be considered, though evidence remains limited. Regular long-term follow-up is essential due to the high recurrence rate and the potential association with internal malignancies.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about Extramammary Paget disease