V8-07: Mapping Biopsies: A New Tactic in the Surgical Management of Extramammary Paget’s Disease
Extramammary Paget's Disease (EMPD) of the penis and scrotum is a rare cutaneous neoplasm first reported by Crocker in 1889. To date, only a small series of case reports of EMPD affecting the scrotum have been described. Over the last century, multiple treatment modalities have been developed in the management of this condition. The most recommended therapeutic modality is complete resection of the skin and subcutaneous tissues of the lesion. _x000D_ _x000D_ Due to the irregular, multicentric nature of EMPD, and the local recurrence rate despite negative intra-operative frozen sections, it was decided to perform mapping biopsies prior to definitive surgical excision and reconstruction in our patient's case. The goal of these biopsies are to provide a template from which to obtain clinically negative margins while preserving as much native tissue as possible during definitive resection. This video presents the surgical outcomes of our case, and explores pre-operative mapping biopsies as a new tactic in the surgical management of Extramammary Paget's Disease.
Our case presentation involves consideration of pre-operative, intra-operative, and post-operative factors. Mapping biopsies were performed prior to complete surgical resection by taking punch-biopsies at the initial lesion margin and at 1cm intervals at the 12, 2, 3, 5, 6, 7, 9, and 10 o'clock positions. Biopsies extended out to 4cm past any visible lesion. Additional biopsies were taken from the 6 and 12 o'clock positions at the base of the penis. Demographics, pathology, and surgical outcomes were reviewed.
Interestingly, our mapping biopsies demonstrated "skip lesions" - where a handful of distal biopsies were positive while comparable biopsies more proximally were negative. This represents disease that likely may have been missed during intra-operative frozen section or while using Moh's surgical techniques. Despite our use of mapping biopsies, our final surgical margins revealed microscopic foci of EMPD in multiple areas of the specimen. No adjuvant therapy was recommended for this finding. At four-weeks post-operatively, the patient was healing well from his excision/reconstructive surgery, and had no evidence of recurrent disease.
Pre-operative mapping biopsies may prove useful as the field of Urology learns more about EMPD and the role surgery plays in its management. Continued research must be conducted to establish the most efficacious and long-lasting treatment for this rare, but often difficult-to-manage disease.