Kidney morcellation in laparoscopic nephrectomy for tumor: recommendations for specimen sampling and pathologic tumor...

Area of Science:

• Urologic Oncology
• Surgical Pathology
• Minimally Invasive Surgery

Background:

• Laparoscopic nephrectomy involves in-situ kidney morcellation, posing challenges for pathological analysis.
• Current guidelines for optimal sampling of morcellated kidney specimens are lacking.
• Morcellation limits complete pathological staging (pTNM), particularly tumor size and vascular invasion.

Purpose of the Study:

• To develop and evaluate specimen sampling protocols for morcellated kidneys from laparoscopic nephrectomy.
• To optimize cost, labor, and diagnostic time for pathological examination.
• To address limitations in pTNM staging due to kidney morcellation.

Main Methods:

• Analysis of 23 laparoscopic nephrectomies/nephroureterectomies.
• Development of a decision analysis model for specimen sampling protocols.
• Calculation of tumor-to-kidney volume ratio (TKR) from imaging and specimen weight.
• Comparison of various sampling algorithms based on TKR.

Main Results:

• An algorithm sampling 5% of the morcellated specimen optimizes cost and labor for TKR >= 0.15.
• Additional sampling may be needed in approximately 25% of cases.
• Complete pathological staging (tumor size, margins, vascular invasion) is severely limited by morcellation.

Conclusions:

• A 5% initial sampling strategy is cost- and labor-efficient for morcellated kidneys with TKR >= 0.15.
• Pathologists require nomograms and consideration of radiologic features for optimal sampling and staging.
• Laparoscopic nephrectomy morcellation significantly impacts the accuracy of pathological tumor staging.