Original Research
External Beam Radiotherapy of Extramammary Paget Disease
Extramammary Paget disease (EMPD) is an insidious intraepithelial neoplasm that is difficult to control with surgery, as large resections...
The most effective treatment of EMPD is margin-controlled surgical excision. High local recurrence rates may be due to irregular margins, multicentricity, and the tendency of EMPD to involve clinically normal-appearing skin. Hendi et al8 noted that EMPD may actually be unifocal with subclinical fingerlike projections extending beyond the main body of the tumor, requiring CK7 immunostaining for visualization to ensure complete margin control. The recurrence rate after standard surgical excision is 33% to 60%. The recurrence rate after excision via Mohs micrographic surgery is 16% for primary EMPD and 50% for recurrent EMPD.9 Other treatment modalities include radiotherapy, topical chemotherapy with 5-fluorouracil or imiquimod, and photodynamic therapy.10-13 Combined systemic chemotherapy with trastuzumab and paclitaxel can be considered for the treatment of ERBB2-positive EMPD.14
For patients with chronic genital or perianal lesions that are unresponsive to treatment, dermatologists should maintain a high index of suspicion for EMPD. If a patient is diagnosed with EMPD, a full-body skin examination should be performed with palpation of all lymph nodes. Imaging studies directed at the anatomic location of the involved skin should be utilized to search for an underlying internal malignancy.
