Accuracy of sentinel node mapping in Marjolin ulcer: comparison of three different injection techniques

Background Marjolin ulcer is a specific type of squamous cell cancer that can benefit from the use of lymphoscintigraphy.The purpose of this study was to evaluate 3 different injection techniques for sentinel node biopsy in patients with Marjolin ulcer. Methods Forty-eight patients with Marjolin ulcer (27 male and 21 female) ranging in age from 24-85 years were included in our study. Intratumoral (IT), peritumoral (PT) and periscar (PS) tissue injections of radiotracer were done in 9, 10, and 29 patients respectively. Injections were done 2-4hours before surgery. Lymphoscintigraphy was done for mapping the lymphatic drainage. During surgery, lymphatic mapping and sentinel node biopsy was performed using a handheld gamma probe. After harvesting sentinel nodes, regional lymph node dissection was done. Result Sentinel node detection rate was higher in the PS group as compared to the IT and PT groups (89.6% vs. 50% and 22.2%) respectively. False negative rate was 0%. Pathologically involved sentinel nodes were detected in 16% of the included patients of our study which led to management change. None of the patients with pathologically non-involved sentinel nodes developed regional lymph node recurrence. Conclusion Lymphatic mapping and sentinel node biopsy is feasible in Marjolin ulcer with high detection rate and low false negative cases which by detection of regional lymph node involvement can potentially change the management of patients. Injection site may be an important factor influencing the success of the procedure and injection of the mapping material in the peri-scar normal skin proximal to the lesion is the best technique.