[A Case of Secondary Extramammary Paget's Disease Developed at 11 Years after Cystectomy]

An 82-year-old woman previously underwent cystectomy and ureterocutaneous ureteral fistula for bacillus calmette guerin-resistant bladder cancer at the age of 70 years old in February 2012. Pathological examination revealed a pTisN0. In October 2020, the patient experienced vulvar itching and pain, which prompted her to consult a gynecologist. Vulvovaginitis was diagnosed, and the patient was observed. However, in June 2023, the vulvar itching persisted, prompting a biopsy for refractory erosions of the vulva. Paget cells were identified in the epidermis, and immunostaining (CK7 (＋), CK20 (＋), p63 (＋), GATA3 (＋), and GCDFP15 (-)) was used to diagnose secondary extramammary Paget's disease due to urothelial carcinoma. Magnetic resonance imaging revealed a 25 mm mass in the pelvic floor, and a biopsy showed the same immunostaining pattern as the skin lesion. Consequently, a diagnosis of local recurrence 11 years after cystectomy and associated secondary extramammary Paget's disease was established. Owing to the evidence of invasion of the mass into the levator ani muscle, she underwent laparoscopic rectal resection plus combined resection of the tumor, perineum, and levator ani muscle in October. Currently, she is 3 months postoperatively without evidence of recurrence.