Table 1. Clinicopathological characteristics of six patients with distal cholangiocarcinoma.

No.	Gender	Age	Histological differentiation	T	N	M	TNM stagea	CA19-9 (U/mL)	Positive lymph nodes	Total lymph nodes	Perineuronal invasion
1	Male	70	Moderate	T2	N0	M0	IIA	40.30	0	37	No
2	Male	62	Moderate-poor	T2	N0	M0	IIA	26.47	0	14	Yes
3	Male	64	Moderate	T3	N1	M1	IV	643.47	1	15	Yes
4	Male	69	Moderate	T3	N0	M0	IIB	74.04	0	21	Yes
5	Male	53	Moderate	T3	N0	M0	IIB	9.16	0	14	Yes
6	Female	56	Poor	T3	N1	M0	IIB	177.21	1	29	Yes

^aTNM stage is based on the 8^th edition of the American Joint Committee on Cancer.

CA 19-9, carbohydrate antigen 19-9.