Oncologic Outcomes of a Novel Mapping Biopsy Technique Before Surgical Excision in the Management of Extramammary Paget Disease

Abstract

Objective To analyze oncologic outcomes of patients with extramammary Paget disease (EMPD) undergoing a novel mapping biopsy before tumor excision (WLE). Methods We analyzed 19 consecutive patients with EMPD treated with biopsy and/or surgical excision at Moffitt Cancer Center from 2013 to 2021. Biopsy technique, patient demographics, pathology, and oncologic outcomes were analyzed. Results In total, 19 patients were included in the analysis. Median age at diagnosis was 72. No patients were diagnosed with secondary malignancy during mandatory workup. Of the 17 patients receiving novel mapping biopsy, 8/17 had at least one positive core biopsy site, with a mean of 7% positivity of the total core sites (4/60). Mapping biopsy positive sites helped shape perimeters for wide local excision (WLE) for patients opting for surgical treatment. Although an extensive mapping biopsy was performed, WLE margins were positive in 11/17 patients. Although positive pathologic margins following surgical excision were prominent, only one patient experienced recurrence of EMPD during a median follow-up period of 38 months. Conclusions We have demonstrated a standardized mapping biopsy before surgical excision in the management of EMPD in men. Despite extensive mapping biopsies, positive surgical margin rates are high, and this may reflect the occult nature of the disease process. Close follow-up is warranted in patients regardless of margin status, but those with positive surgical margins may benefit from more aggressive regimens.