A Primer on Extramammary Paget's Disease for the Urologist

Joon Yau Leong; Paul H. Chung


Transl Androl Urol. 2020;9(1):93-105. 

In This Article

Clinical Presentation

EMPD most commonly presents as a well delineated or poorly defined erythematous and scaly plaque that may encrust, ulcerate or develop pigmentation (Figure 1).[17] Due to its similar clinical presentation to many benign conditions, the diagnosis of EMPD is often delayed for years, with only 17% of patients being correctly diagnosed at first presentation.[18] The most common presenting symptoms include pruritus (up to 60–72%), rash or erythema, which usually raises little suspicion for a malignant etiology.[19,20] The initial differential diagnoses are commonly contact dermatitis, seborrheic eczema and fungal infections.[12,18] Thus, conservative management such as topical emollients or corticosteroids, antifungal creams or other oral therapies are often prescribed first for these benign conditions. Patients typically experience a delay in definitive diagnosis for an average of 21 to 43 months after multiple rounds of failed treatment and persistent symptoms.[10,11] Therefore, providers should biopsy any recalcitrant lesions that fail to respond to expectant treatments or acquire a specialist referral to decrease the risk of delayed diagnosis.

Figure 1.

Genital EMPD can present as a well delineated or poorly defined erythematous lesion that may affect the (A) scrotal, (B) suprapubic, (C) inguinal or (D) perineal regions of the body. EMPD, extramammary Paget's disease.

On histology, lesions usually reveal an epidermal infiltration of Paget cells, which appear as large, round cells with an abundant, pale-pink cytoplasm, surrounding a hypochromatic nuclei, occasionally with a prominent nucleolus.[21] Pathognomonic cells contain intracytoplasmic sialomucin, which is capable of staining periodic acid-Schiff (PAS), mucicarmine, colloidal iron and alcian blue stains, which can aid in the diagnosis of EMPD.[9] Cells may also express cytokeratin (CK), which are easily identifiable on immunochemical staining. While CK7 has been reported to have good sensitivity for EMPD, ranging from 86–100%, CK20 appears to be more specific for this disease.[22–24] The expression of hormonal receptors has also been examined. A lack of both the estrogen and progesterone receptors together with the presence of androgen receptors and overexpression of HER-2 protein is often suggestive of EMPD.[25,26] Furthermore, the presence of tumor suppressor protein p53 as well as the expression of tumor proliferation markers, such as Ki-67 and cyclin D1, has been linked to the secondary form of EMPD, which also predicts the invasiveness of EMPD lesions.[27,28] While there are no grading systems for EMPD histology, the unified perception is that all EMPD lesions are considered high grade.[29]