Frozen section and permanent diagnoses of the bile duct margin in gallbladder and bile duct cancer

Hypothesis. Frozen section diagnosis and permanent diagnosis of bile duct margin predict local recurrence after surgical resection of gallbladder or bile duct carcinoma. Design. Retrospective review. Setting. University, tertiary care. Patients. A total of 20 patients underwent frozen section diagnosis of bile duct margin for resection of gallbladder and bile duct carcinoma. Main outcome. Diagnosis of frozen and permanent section of bile duct margin, and local recurrence. Results. The permanent diagnosis was identical in 15 patients but changed in 5 (from positive to negative in 3 and from negative to positive in 2). The reasons for these changes were overdiagnosis (mucosal lesions in two and mesenchymal components in another) and new recognition of malignant cells on permanent section in the other two. In seven patients with a positive bile duct margin by permanent histology, mucosal spread was evident in two and involvement of the subepithelial layer was present in the other five. No local recurrence occurred in the two patients with epithelial spread and four of the five with subepithelial infiltration. Conclusions. Frozen section and permanent diagnoses of the bile duct margin in gallbladder and bile duct carcinoma may be inconsistent in 25% of patients due to overdiagnosis of frozen section or new recognition of cancer cells by permanent histology. In situ carcinoma does not always produce local recurrence, while cancer cells in the subepithelial layer strongly predict occurrence of local recurrence.