[Lymphatic mapping and sentinel node biopsy in penis cancer. Feasibility study and preliminary report]

Most patients with invasive squamous cell carcinoma of the penis do not have inguinal node metastasis at the time of diagnosis and 50% of those having palpable nodes are inflammatory. Penis cancer (PC) treatment implies resection of the primary tumor and inguinal lymphadenectomy; nevertheless, morbidity related to this procedure is high and its usefulness may be questioned in patients without metastasis in dissected nodes. Lymphatic mapping with sentinel node biopsy (LMSNB) is a valid alternative, useful in other neoplasias. The objective of this study is to determine if it is possible to identify a sentinel node (SN) in patients with PC. Patients with T1-2 PC without palpable nodes (N0) were included. LMSNB was carried out with the combined technique (blue dye and radiocolloid). All patients underwent an elective bilateral inguinal lymphadenectomy. Sensitivity and false negative index were calculated. SNs were sent for transoperative study with imprint technique and, definitively, with serial cuts and hematoxylin/eosin staining. Nine patients showed results with 32 lymph carrier zones and SN was identified in all of them, 4 regions had metastasis, in 3 the SN was metastatic and in one patient was metastasis-negative (false negative); sensitivity = 80%; false negatives index = 20%. Seven patients (77%) did not have node metastasis. LMSNB is an alternative for staging PC patients and could prevent unnecessary inguinal lymphadenectomies. A larger number of patients is required to validate the sturdy. The combined technique offers a high rate of success in SN identification.