Recurrence of Noninvasive Perianal Extramammary Paget's Disease in the Lymph Nodes without Local Recurrence after Complete Excision

Primary extramammary Paget's disease (EMPD) is a rare intraepithelial adenocarcinoma. Lymph node metastasis from noninvasive EMPD originating in the anorectal region is extremely rare, and the recurrence of noninvasive EMPD is commonly associated with local recurrence mainly due to an insufficient resection margin. We herein report a case of inguinal and para-aortic lymph node recurrence without local recurrence after complete margin-free surgical resection of noninvasive perianal EMPD. The patient was a man in his 40s who presented with an erythematous plaque of 7 × 5 cm in the perianal region, which had been present for 1 year. Biopsy from the perianal skin suggested EMPD; it was positive for cytokeratin (CK)7 and negative for CK20. Underlying malignancy was ruled out based on whole-body enhanced computed tomography (CT) and total colonoscopy. Surgery including complete wide resection of the lesion with preservation of the rectum was performed, and VY-advancement flap reconstruction and flap-rectum anastomosis were performed. A histological examination of the whole specimen with 5-mm slices confirmed noninvasive EMPD resected with all-negative surgical margins. At 2 years and 6 months after surgery, however, enlargement of the inguinal and para-aortic lymph nodes was detected by follow-up enhanced CT, and the recurrence of EMPD was diagnosed based on left inguinal lymph node biopsy. The patient underwent chemotherapy without a remarkable response. He died of the disease 53 months after the first surgery. This is the first case report of lymph node metastasis without local recurrence after complete margin-free resection of noninvasive perianal EMPD.