Table 5.

Scoring of intraductal ultrasononographic findings and frequency of malignancy on final diagnosis

No positive factors on IDUS	Frequency of malignancy on final diagnosis*
(1) Total cases (n=62)
0	2/17 (12%)
1	5/7 (71%)
2–3	37/38 (97%)
(2) Cases with no evidence of malignancy on the histological findings of biopsy specimen (n=31)
0	0/15 (0%)
1	2/4 (50%)
2–3	11/12 (92%)

Positive factors in predicting malignancy on intraductal ultrasonography (IDUS ) findings: (1) presence of sessile tumour (intraductal or outside of the bile duct); (2) tumour size greater than 10.0 mm; and (3) interrupted wall structure.

*The process of final diagnosis is shown in table 4 ▶.