Endoscopic ultrasonography does not differentiate neoplastic from non-neoplastic small gallbladder polyps

Table 1 Histological diagnosis and size of polypoid gallbladder lesions in the surgical series (n)

Size (mm)	Cholesterol	Adenomyomatosis	Inflammatory	Adenoma	Cancer	Total
5-10	39	9	0	10	0	58
11-15	14	7	1	3	1	26
16-20	3	1	1	4	1	10

Table 2 EUS and US diagnosis of polypoid gallbladder lesions in the surgical series

	Pathologic diagnosis (n)
	Cholesterol polyp	Adenomyomatosis	Inflammatory polyp	Neoplastic lesions
EUS diagnosis
Cholesterol	47	4	0	7
Adenomayomatosis	0	11	1	0
Neoplastic lesion	9	2	1	12
US diagnosis
Cholesterol	41	8	0	10
Adenomayomatosis	0	4	1	0
Neoplastic lesion	15	5	1	9

Table 3 EUS and US diagnosis according to the size of the polypoid gallbladder lesion

	Pathology (n)
	Cholesterol		Adenomyomatosis		Neoplastic lesion
Size (mm)	5-10	11-20	5-10	11-20	5-10	11-20
EUS
Cholesterol	33	14	0	0	6	3
Adenomyomatosis	6	0	4	7	1	1
Inflammatory	0	0	0	1	0	1
Neoplastic lesions	4	1	0	0	4	8
US
Cholesterol	32	9	0	0	7	8
Adenomyomatosis	7	1	1	3	1	4
Inflammatory	0	0	0	1	0	1
Neoplastic lesions	8	2	0	0	2	7

Table 4 Differential diagnosis between neoplastic and benign polyps by EUS and US

	Diagnosis by postoperative histological examination
	Neoplastic polyp	Non-neoplastic polyp
Diagnosis by EUS
Neoplastic polyps	12	12
Non-neoplastic polyps	6	64
Diagnosis by US
Neoplastic polyps	9	21
Non-neoplastic polyps	10	54

Table 5 Sensitivity, specificity, and accuracy of EUS and US diagnoses for neoplastic lesions according to the size of the polypoid gallbladder lesion (%)

	Sensitivity	Specificity	PPV	NPV	Accuracy
EUS
Overall	66.7	84.2	50.0	91.4	80.9
5-10 mm	44.4	86.0	36.4	89.6	79.7
11-20 mm	88.9	81.5	61.5	95.7	83.3
US
Overall	47.4	72.0	30.0	84.4	67.0
5-10 mm	20.0	83.3	20.0	83.3	72.4
11-20 mm	77.8	51.9	35.0	87.5	63.9

PPV: Positive predictive value; NPV: Negative predictive value.