Cadaveric evidence on lymph node counts and grossing accuracy in pelvic lymph node dissection for prostate cancer staging

Abstract

Pelvic lymph node dissection (PLND) remains the most accurate method for staging prostate cancer, yet the adequacy of nodal yield and the absence of standardized specimen processing remain unresolved. This cadaveric study aimed to establish histologically verified benchmarks for lymph node number, size, and detectability. Super-extended PLND was performed in 13 male soft-embalmed cadavers prepared with arterial silicone injection. Specimens were grossed under stereomicroscopy, and all tissue was submitted for histology. A total of 641 lymph nodes were identified, with a median of 46 nodes per cadaver (range 17–92). All extended dissections exceeded the commonly proposed minimum threshold of 10 nodes. The median lymph node size was 4.1 mm, but only 58.1% were detected grossly, while 41.9% were identified exclusively by histology. Detection was strongly size-dependent, with logistic regression showing a 1.12-fold increase in odds for each additional millimeter in node size. These findings demonstrate substantial anatomical variability and highlight the limitations of gross-only protocols, which underestimate nodal yield and risk missing small nodes. Our results support extended PLND as a more reliable staging approach than limited dissection and emphasize the value of total histological submission to ensure accurate pathological staging in prostate cancer.