A case of pagetoid spread of urothelial carcinoma with notable reduction achieved through enfortumab vedotin, resulting in complete surgical resection.

Secondary extramammary Paget's disease is a rare condition associated with the contiguous extension of tumor cells from the underlying adnexal structures, genitourinary, or gastrointestinal tracts. We report the case of an 80-year-old female with a 7-year history of urothelial carcinoma who presented with erythema of the labia majora. The diagnosis was pagetoid spread of urothelial carcinoma. The patient declined surgical resection of the lesion. She underwent nine cycles of first-line platinum-based chemotherapy and received one course of pembrolizumab for metastatic urothelial carcinoma. As the lesion progressively enlarged, third-line therapy with enfortumab vedotin was initiated, which resulted in significant tumor reduction. This allowed for a successful surgical complete resection of the tumor. Enfortumab vedotin was highly effective and demonstrated dramatic efficacy for controlling extramammary Paget's disease secondary to urothelial carcinoma.