High diagnostic accuracy of inguinal ultrasonography and fine-needle aspiration followed by dynamic sentinel lymph node biopsy in men with impalpable and palpable inguinal lymph nodes.

Abstract

To assess the accuracy of dynamic sentinel lymph node biopsy (DSNB) after negative ultrasonography (US) guided fine-needle aspiration (FNA) for inguinal lymph node (ILN) staging. We performed a retrospective analysis of men with ≥T1G2 penile cancer and negative inguinal US-guided FNA undergoing DSNB. Men with suspicious US but negative FNA underwent US-guided ILN excision. Men with ≥T1G2 local recurrence during follow-up and non-squamous cell histologies were excluded. Descriptive analysis was performed, and sensitivity and negative predictive values (NPVs) were calculated. We included 403 men with 728 groins with negative FNA undergoing DSNB ± US-guided LN excision. At least one sentinel LN (SN) was visualised in 93% during the first and in 7% during the second lymphoscintigraphy. The median SNs visualised preoperatively was 1 SN and a median of 2 LNs were resected. ILN metastases were detected in 9% groins in men with impalpable and in 17% men with palpable LNs. Stratified by impalpable and palpable ILN, non-local recurrence despite pathologically negative DSNBs was seen in 0.5% and 0%, respectively. Limited to men with ≥24 months follow-up, non-local recurrence after negative DSNBs was seen in 0.4% and 0%, respectively. The sensitivity of DSNB was 96% and the NPV was 100%. The main limitation of this analysis is its retrospective nature with inherit biases. Inguinal US and FNA followed by DSNB can accurately stage men with both impalpable and palpable ILN, which provides logistical and surgical advantages.