Indications for Sentinel Node Biopsy for Patients with Extramammary Paget’s Disease Based on the Kobe University Hospital Experience

Abstract

Background and Objectives: In extramammary Pagets disease (EPD), the prognosis is serious in cases in which the tumor cells invade into the dermis from the epidermis or metastasis to lymph nodes occur. Recently, some authors have suggested the usefulness of a sentinel node biopsy, but there is a paucity of data for EPD. We review the usefulness and the indications for sentinel node biopsy in EPD. Methods: The study included a retrospective analysis of 35 patients with EPD. (SNB was performed in 17 cases, and we compared the pre-and-post operative clinical appearance and histological findings in the two groups. Results: We found discrepancies in the histological findings (invasion level) between the biopsy specimens and the postoperative specimens. However in 18 of 25 cases which included erosions, indurated plaques, or nodules at the first clinical presentation, dermal invasions of tumor cells were histologically detected. Dermal invasions were not found in the 4 patients without clinical findings suggesting dermal invasion (erosions, indurated plaques, or nodules). In our study, the identification rate of SNB was 95.7%, and the correct diagnosis rate was 100%. Conclusion: Our study indicated that, in some cases, it was impossible to predict the presence of the dermal invasion of Pagetʼs cells based only on the preoperative biopsy specimen. SNB is strongly recommended when indurated plaques, erosions, and nodules are found in EPD lesions.