Theodorus van der Kwast

Background Extramammary Paget disease (EMPD) is an uncommon disease affecting older men and women. Clinically, it appears as a plaque lesion with an erythematous or leukoplakic background in regions with abundant apocrine glands such as female external genitalia, perineum, scrotum, and penis. Methods We are presenting an 85‐year‐old patient with recurrent erythematous plaque lesions involving the penis and known to have urothelial carcinoma (UC) in situ of the bladder. A literature review of EMPD secondary to UC has been conducted through PubMed and Google Scholar search engines. Results The histopathologic examination revealed a proliferation of Paget cells within the surface squamous epithelium. The lesional cells displayed vesicular nuclei, clear cytoplasm, and a positive staining for CK7, CK20, HER2, GATA3 as well as p40, and negative staining for SOX10, CK5/6, and CDX2. The literature review revealed 18 more cases of EMPD associated with UC, including 4 with non‐invasive UC. Most of them were treated surgically, but the disease recurred in nine cases and death of disease was reported in at least four patients, all of them associated with invasive UC. Conclusion The prognosis of penile EMPD seems to be dictated by the stage of the underlying UC.