Background: The aim of this study was to evaluate the role of computed tomography (CT), Cloquet's node, and disease burden of inguinal lymph nodes (LNs) in predicting pelvic lymph node metastases (LNM) of penile cancer.
Patients and methods: Bilateral inguinal lymph node dissection was performed in 73 penile cancer patients and revealed that 33 groin basins exhibited inguinal LNM.
Results: Of the 33 groin basins, 16 (48.5%) had pelvic LNM. The sensitivity of pelvic CT in detecting metastatic LNs was 37.5%, and the specificity was 100%. Cloquet's node had a sensitivity of 30.0% and a specificity of 94.1% in pelvic CT-negative groin basins. Pathological characteristics of the inguinal LNs - number of positive LNs, lymph node ratio (number of positive LNs/total number removed), extranodal extension and the expression of p53 - were significantly associated with pelvic LNM. Furthermore, enlarged inguinal LNs = 3 in preoperative CT imaging and lymph node size = 3.5 cm in long diameter were prognostic factors for pelvic LNM (p = 0.001 and 0.003, respectively).
Conclusion: Pelvic CT imaging and tumor status of Cloquet's node is of limited use in predicting microscopic pelvic LNM. Pathological characteristics of the inguinal LNs remain the essential indicators of pelvic LNM.