Intraoperative frozen section diagnosis of bile duct margin for extrahepatic cholangiocarcinoma

Table 1 Clinicopathological characteristics of extrahepatic cholangiocarcinoma

	pCCA (n = 34)	dCCA (n = 40)
Age (yr), median (range)	71.5 (44-82)	72.5 (39-85)
Gender
Male	23	6
Female	11	34
Preoperative biliary drainage
Yes	33	38
No	1	2
Procedure
PD	1	38
HH	27	1
PD + HH	5	0
Bile duct resection	0	1
Others	1	0
Total number of duct margins for frozen section	55	45
Number of duct margins for frozen section
1	15	35
2	17	5
3	2	0
pT
pT1/pT2	27	20
pT3/pT4	6	19
Unknown	1	1

dCCA: Distal cholangiocarcinoma; HH: Hemihepatectomy; pCCA: Perihilar cholangiocarcinoma; PD: Pancreaticoduodenectomy.

Table 2 Histopathological results of the biliary duct margins

	Negative (%)	Borderline (%)	Positive (%)	Total (%)	P value
Margin level
Total layer
FSD	41 (41.0)	39 (39.0)	20 (20.0)	100 (100)	0.039
PSD	56 (56.0)	23 (23.0)	21 (21.0)	100 (100)
Epithelial layer
FSD	44 (44.0)	41 (41.0)	15 (15.0)	100 (100)	0.078
PSD	59 (59.0)	27 (27.0)	14 (14.0)	100 (100)
Subepithelial layer
FSD	87 (87.0)	1 (1.0)	12 (11.0)	100 (100)	0.560
PSD	86 (86.0)	0 (0.0)	14 (14.0)	100 (100)
Patient level
Total layer
FSD	26 (35.1)	31 (41.9)	17 (23.0)	74 (100)	0.134
PSD	36 (48.7)	20 (27.0)	18 (24.3)	74 (100)

FSD: Frozen section diagnosis; PSD: Permanent section diagnosis.

Table 3 Concordance rate between frozen section diagnosis and permanent section diagnosis

	Concordance rate (%)	Sensitivity (%)	Specificity (%)	Positive-predictive value (%)	Negative-predictive value (%)
Original diagnostic results
Total layer	68.0	85.7	66.1	90.0	90.2
Epithelial layer	69.0	78.6	64.6	73.3	86.4
Subepithelial layer	98.0	85.7	100.0	100.0	98.9
Revised diagnostic results
Total layer	95.0	85.7	97.5	90.0	97.5
Epithelial layer	93.0	70.0	95.6	73.3	96.5
Subepithelial layer	98.0	85.7	100.0	100.0	98.9

Table 4 Extent of the remaining epithelium and diagnostic results of the bile duct margin

	Extent of the remaining epithelium	Negative (%)	Borderline (%)	Positive (%)	Total (%)
FSD
	E1 (0%-24%)	22 (66.6)	9 (27.3)	2 (6.1)	33 (100)
	E2 (25%-49%)	8 (38.1)	11 (52.4)	2 (9.5)	21 (100)
	E3 (50%-100%)	14 (30.4)	21 (45.7)	11 (23.9)	46 (100)
PSD
	E1 (0%-24%)	22 (68.7)	7 (21.9)	3 (9.4)	32 (100)
	E2 (25%-49%)	9 (42.9)	9 (42.9)	3 (14.3)	21 (100)
	E3 (50%-100%)	28 (59.6)	11 (23.4)	8 (17.0)	47 (100)

FSD: Frozen section diagnosis; PSD: Permanent section diagnosis.

Table 5 Diagnostic discordance between frozen section diagnosis and permanent section diagnosis

	Diagnostic discordance		Total (%)
	Yes (%)	No (%)
Epithelial layer	31 (31.0)	69 (69.0)	100 (100)
pCCA	21 (38.2)	34 (61.8)	55 (100)
dCCA	10 (22.2)	35 (77.8)	45 (100)
Subepithelial layer	2 (2.0)	98 (98.0)	100 (100)
pCCA	1 (1.8)	54 (98.2)	55 (100)
dCCA	1 (2.2)	44 (97.8)	45 (100)
Total layer	28 (28.0)	72 (72.0)	100 (100)
pCCA	18 (32.7)	37 (67.3)	55 (100)
dCCA	10 (22.2)	35 (77.8)	45 (100)

pCCA: Perihilar cholangiocarcinoma; dCCA: Distal cholangiocarcinoma.

Table 6 Details of diagnostic discordance between frozen section diagnosis and permanent section diagnosis

	Epithelial layer (pCCA:dCCA)	Subepithelial layer (pCCA:dCCA)
From negative to borderline	4 (2:2)	0 (0:0)
From negative to positive	1 (0:1)	1 (1:0)
From borderline to negative	20 (13:7)	0 (0:0)
From borderline to positive	2 (2:0)	1 (0:1)
From positive to borderline	4 (4:0)	0 (0:0)
Total	31 (21:10)	2 (1:1)

pCCA: Perihilar cholangiocarcinoma; dCCA: Distal cholangiocarcinoma.

Table 7 Local recurrence-free survival rates of patients according to the status of the bile duct margin evaluated by frozen section diagnosis

	Duration (yr)	Negative	Borderline	Positive
Total layer
Number of cases		26	31	17
	1	0.916	0.918	0.518
	3	0.769	0.725	0.194
	5	0.769	0.725	0.194
1Epithelial layer
Number of cases		26	30	6
	1	0.916	0.915	0.333
	3	0.769	0.722	0.000
	5	0.769	0.722	0.000

¹Patients with borderline or positive subepithelial layer were excluded.

Table 8 Local recurrence-free survival rates of patients according to the status of the bile duct margin evaluated by permanent section diagnosis

	Duration (yr)	Negative	Borderline	Positive
Total layer
Number of cases		36	20	18
	1	0.940	0.862	0.667
	3	0.710	0.790	0.356
	5	0.710	ND	ND
1Epithelial layer
Number of cases		36	20	6
	1	0.940	0.862	0.333
	3	0.710	0.790	0.167
	5	0.710	ND	ND

¹Patients with borderline or positive subepithelial layer were excluded. ND: Not determined.