Radiation Oncology/EMPD

Extramammary Paget's Disease Overview Intraepithelial neoplasm with glandular differentiation Morphologically the same as Paget's disease of the breast, but unlike in the nipple, there is only rarely an underlying malignancy. It appears to be a primary epithelial malignancy Areas of involvement: peno-scrotal area, perineum, perianal area, vulva, axillae, groin, umbilicus, eyelid Tends to arise in sites where apocrine glands are present in high concentration In cases with an underlying malignancy (~20% of cases), it is often a cutaneous adnexal carcinoma, usually of apocrine or eccrine glands Presenting symptoms: pruritus, scaly eczematous lesion Histology shows presence of Paget cells, which are large cells with abundant basophilic cytoplasm and a large hyperchromatic and pleomorphic nucleus. Staining positive for CEA, CK7, EMA, and CAM 5.2; may also show overexpression of Her2 Internal malignancies (e.g. colon, ovarian) may be associated in 10-20% Primary treatment is surgery, but margin may be diffuse and difficult to clear. Suggested margins have been 3-5cm, Mohs should be considered RT reasonable alternative if patient not a surgical candidate Literature Hong Kong; 2007 17665242 -- "Extramammary Paget's Disease in Chinese Males: A 21-year Experience." (Chiu TW, World J Surg. 2007 Oct;31(10):1941-6.) Retrospective. Outcome: recurrence rate 35% (simple WLE 60% vs. intraop frozen sections 25%)