Differential diagnosis of benign and malignant branch duct intraductal papillary mucinous neoplasm using contrast-enhanced endoscopic ultrasonography

Table 1 Clinical features of the 35 patients who were monitored

	Follow-up cases (n = 35)
Sex, M/F	18/17
Mean age ± SD, yr	67.9 ± 10.2
Mean follow-up period ± SD, mo	27.4 ± 16.7
Cyst size
Initial examination ± SD, mm	27.0 ± 11.8
Last examination ± SD, mm	30.1 ± 13.1
Changes of the cyst size
No change	29
Enlarged (≥ 10 mm)	5
Reduced (≥ 10 mm)	1
MPD diameter
Initial examination ± SD, mm	3.2 ± 1.8
Last examination ± SD, mm	3.5 ± 2.2
Changes in MPD diameter
No change	26
Enlarged (≥ 1 mm)	7
Reduced (≥ 1 mm)	2
Appearance of MNs during follow-up period	0
Followed up > 12 mo	33
Resected after follow-up	2
Pathological diagnosis
Low-grade dysplasia	0
Intermediate-grade dysplasia	0
High-grade dysplasia	2
Invasive adenocarcinoma	0

MPD: Mail pancreatic duct; MNs: Mural nodules.

Table 2 Ability to diagnose the presence of mural nodules with each imaging modality

	Sensitivity (95%CI)	Specificity (95%CI)	PPV (95%CI)	NPV (95%CI)	Accuracy (95%CI)
CT	71% (0.42-0.92)	100% (0.90-1.00)	100% (0.69-1.00)	90% (0.76-0.98)	92% (0.80-0.98)
EUS alone	100% (0.77-1.00)	61% (0.43-0.77)	50% (0.31-0.70)	100% (0.85-1.00)	72% (0.58-0.84)
EUS combined with CE-EUS	100% (0.76-1.00)	97% (0.85-1.00)	93% (0.66-1.00)	100% (0.90-1.00)	98% (0.89-1.00)

CT: Computed tomography; EUS: Endoscopic ultrasonography; CE-EUS: Contrast-enhanced EUS; PPV: Positive predictive value; NPV: Negative predictive value; CI: Confidence interval.

Table 3 Clinicopathologic features of the 15 patients who underwent a resection

Case	Cyst size (mm)	MPD diameter (mm)	MNs								Pathological diagnosis
			CT		EUS		CE-EUS		Pathology
			Presence	HCT (mm)	Presence	HEUS (mm)	Presence	HCE-EUS (mm)	Presence	HPath (mm)
1	36	12	+	23.4	+	25.2	+	22.2	+	21.2	IC
2	30	12	+	21.3	+	20.1	+	19.2	+	19.8	IC
3	40	12	+	13.9	+	19.1	+	17.6	+	17.2	IC
4	20	8	+	22.1	+	23.6	+	21.5	+	17.2	IC
5	50	2	+	18.9	+	15.2	+	14.3	+	13.1	IC
6	20	6	+	13.1	+	11.5	+	10.4	+	9.8	IC
7	30	9	+	14.4	+	10.6	+	9.5	+	9.3	IC
8	18	8	-	0	+	10.1	+	8.8	+	9.2	IC
9	38	6	-	0	+	10.9	+	9.7	+	9.1	IC
10	27	3	+	5.0	+	12.5	+	10.1	+	7.6	IC
11	25	13	+	11.3	+	13.8	+	10.3	+	10.1	HGD
12	30	6	+	6.4	+	10.1	+	8.5	+	7.3	HGD
13	30	6	-	0	+	10.5	+	8.4	+	5.3	HGD
14	31	12	-	0	+	2.3	+	2.3	+	2.1	HGD
15	28	3	-	0	+	3.9	+	2.7	-	0	ImGD

MPD: Main pancreatic duct; MNs: Mural nodules; CT: Computed tomography; EUS: Endoscopic ultrasonography; CE-EUS: Contrast-enhanced EUS; IC: Invasive carcinoma; HGD: High-grade dysplasia; ImGD: Intermediate-grade dysplasia; H_CT: MN height measured by CT; H_EUS: MN height measured by EUS; H_CE-EUS: MN height measured by CE-EUS; H_Path: MN height measured on pathological specimens.

Table 4 Optimum cut-off values for mural nodule height to differentiate between benign and malignant branch duct intraductal papillary mucinous neoplasm using mural nodule height as measured using each imaging modality or pathological specimens

	AUC	Cutoff value (mm)	Sensitivity (95%CI)	Specificity (95%CI)	Accuracy (95%CI)
CT	0.82	13.1	70 (0.35-0.93)	100 (0.48-1.00)	80 (0.51-0.96)
EUS	0.87	10.6	90 (0.53-1.00)	80 (0.27-1.00)	87 (0.58-0.99)
CE-EUS	0.92	8.8	100 (0.69-1.00)	80 (0.27-1.00)	93 (0.66-1.00)
Pathological specimens	0.90	7.6	100 (0.69-1.00)	80 (0.27-1.00)	93 (0.66-1.00)

CT: Computed tomography; EUS: Endoscopic ultrasonography; CE-EUS: Contrast-enhanced EUS; AUC: Area under the curve.