Evaluating the accuracy of intraoperative frozen section during inguinal lymph node dissection in penile cancer

Inguinal lymph node dissection is an integral part in the management of invasive penile tumors with intraoperative assessment often aiding decision-making during dissection. In this study, we evaluate the diagnostic value of intraoperative frozen section (FS) and analyze clinicopathologic factors that affect its accuracy.

We, retrospectively, reviewed 84 patients with squamous cell carcinoma of the penis who underwent inguinal lymph node dissection at our institution. Intraoperative FS from the superficial inguinal nodes was available in 65 patients and compared with correspondent permanent sections (pathologic node staging [pN]). Sensitivity and specificity were calculated and factors associated with a false negative event were analyzed using logistic regression.

The total positive node rate was 60% (39/65). Of 39 pN+ cases, 10 (25.6%) had false-negative FS, whereas the remaining 29 were concordant intraoperatively. Sensitivity and specificity were 0.74 and 1, respectively. On univariable analysis, higher body mass index was associated with a false negative event although there was no association with age, receipt of neoadjuvant therapy, or clinical node stage.

Intraoperative FS is highly specific and moderately sensitive for the detection of positive superficial inguinal lymph nodes in penile cancer. Its use can help guide intraoperative surgical planning while limiting its reliance for patients with higher body mass index.