Sentinel node biopsy in carcinoma penis using methylene blue dye technique

Abstract

Purpose : Penile carcinoma is a common disease in India. This paper shows the results of sentinel node biopsy using methylene blue and discusses the incidence of false-negative rates. Materials and Methods: From September 2005 to March 2008, 22 newly diagnosed penile carcinoma patients (T1, T2, N0) were included in this prospective study. Intraoperative lymphatic mapping was done using methylene blue dye and the sentinel node was identified and removed. Lymphadenectomy was performed for positive inguinal lymph node metastasis. Results : There were 22 patients (mean age 52.7). The tumors were mostly located in the glans (73%). Eighty six percent was T1 lesions and 14% was T2. Ninety one percent of the patients underwent partial penectomy, and 9% underwent total penectomy. Sentinel node was identified in 20 patients (90.9%). In total, 49 sentinel nodes were identified (2.45 nodes per person). Only one patient had a positive pathological lymph node metastasis at the time of the surgery. Additionally, two patients became inguinal lymph node positive at the follow-up. This data yielded a sensitivity rate of 33% and a false-negative rate of 66%. There were no complications due to methylene blue. Conclusion : Sentinel node biopsy using only methylene blue for penile carcinoma has a very low sensitivity and a high false-negative rate. However, methylene blue can be used as a substitute for lymphazurin.