乳腺外Paget's病在臨床上是一種相當少見的表皮內的腫瘤，其成因會與源自汗腺的癌症或是體內的惡性腫瘤有關。約有四成的患者可以檢查出其他器官的癌症，然而即使沒有潛在的腫瘤乳腺外Paget's病，仍有一定的比例會遠處轉移，足見此病的惡性度。我們報告一位78歲男性因陰莖上乳腺外Paget's病，臨床上表現陰莖搔癢持續2個月後，接受大範圍切除而成功治療的案例。

Extramammary Paget's disease (EMPD) is an uncommon intraepidermal neoplasm. The possible etiology of EMPD is an underlying carcinoma of the sweat glands, and it can be associated with an internal malignancy. The incidence of distant organ malignancies of EMPD can be as high as 40%; however, even in the absence of an identified internal malignancy, EMPD may occasionally produce distant metastases, indicating the malignant potential of EMPD. We review the literature and report 1 case of EMPD involving the penile shaft. A 78-year-old man presented with an eczema-like itching lesion penile shaft for 2 months. Wide excision with a safety margin of 3 cm, followed by a split thickness skin graft (STSG) from the right thigh of the patient was performed. The pathology revealed Paget's disease, while surveillance for an associated malignancy was negative. There was no recurrence nor identified internal cancer at an 18 months of follow-up.