Background: Although frozen section is recommended to prevent tumor dissemination following laparoscopic cholecystectomy (LC) for unsuspected gallbladder cancer, there are no reports concretely demonstrating its effectiveness and outcome.
Methods: Frozen section during LC was performed in 990 patients with gallstones. The sensitivity, specificity of frozen section, and false-negative cases were evaluated in comparison with postoperative entire cross sections.
Results: In frozen section, 983 cases were diagnosed as benign and 7 cases as malignant. Of the benign cases, cancer was discovered in 4 patients postoperatively in which frozen section was diagnosed as regenerative epithelial severe atypia. Sensitivity was 64% and specificity was 100%. Concerning the results of frozen section by p-TNM classification, cancer was diagnosed in 40% of Tis lesions, whereas it was found in 83% of T2 or T3 lesions.
Conclusion: Frozen section is effective in cases with T2 or greater lesions for which conversion to radical surgery should be required.