KIT-negative gastrointestinal stromal tumors with a long term follow-up: A new subgroup does exist

Table 1 Clinicopathological features of KIT-negative cases

CaseNo.	Sex	Age (yr)	Symptoms	Site	Size	Mitoses(/50 HPF)	Presenceof necrosis	Morphology	Risk category	Clinicalstatus	Survivaldata/mo
					(cm)
1	M	60	Yes	Small Intestine	4.30	1	No	Epithelioid	Low risk	Primary	Alive/12
2	M	46	No	Stomach	0.50	0	No	Mixed	Very low risk	Primary	Alive/24
3	M	50	No	Small Intestine	0.50	0	No	Anaplastic	Very low risk	Primary	Alive/24
4	M	64	Yes	Large Intestine	4.50	10	Yes	Epithelioid	High risk	Liver metastasis	Dead/12
5	M	78	Yes	Small Intestine	7.00	1	Yes	Mixed	Intermediate risk	Liver metastasis	Dead/12
6	F	53	Yes	Stomach	5.00	0	No	Spindled	Low risk	Primary	Alive/47
7	M	43	Yes	Esophagus	7.00	0	No	Mixed	Intermediate risk	Primary	Alive/25
8	M	51	Yes	Small Intestine	6.00	2	Yes	Epithelioid	Intermediate risk	Primary	Alive/12
9	M	69	No	Stomach	2.00	0	No	Mixed	Very low risk	Primary	Alive/37
10	M	54	Yes	Stomach	3.50	0	No	Spindled	Low risk	Primary	Alive/62
11	M	70	Yes	Stomach	6.00	0	No	Anaplastic	Intermediate risk	Primary	Alive/82
12	M	42	Yes	Stomach	6.00	2	No	Anaplastic	Intermediate risk	Primary	Alive/56
13	M	26	No	Stomach	0.50	0	No	Epithelioid	Very low risk	Primary	Alive/78
14	M	82	Yes	Stomach	30.00	6	Yes	Mixed	High risk	Primary	Alive/82
15	M	61	Yes	Small Intestine	3.00	29	No	Mixed	High risk	Liver metastasis	Dead/2

M = male; F = female.

Table 2 Correlation between gender and CD117 expression in patients with GISTs

		CD117 expression
		Negative	Positive	Total
Gender	Male	14	17	31
		45.20%	54.80%	100%
	Female	1	18	19
		5.30%	94.70%	100%
Total		15	35	50

Table 3 Correlation between tumor location and CD117 expression in patients with GISTs

Tumor location		CD117 expression
		Negative	Positive	Total
Esophagus		1	2	3
		33.30%	66.70%	100%
Stomach		8	11	19
		42.10%	57.90%	100%
Small intestine		5	18	23
		21.70%	78.30%	100%
Large intestine		1	4	5
		20%	80%	100%
Total		15	35	50
		30%	70%	100%

Table 4 Immunohistohemical findings of patients with KIT-negative GISTs

		Immunohistochemistry
CaseNo.	CD117	α-SMA	Desmin	S-100	NSE	CD34
1	Negative	Positive	Positive	-	-	Positive
2	Negative	-	Positive	Positive	-	-
3	Negative	-	-	-	-	Positive
4	Negative	Positive	-	-	-	Positive
5	Negative	Positive	-	-	Positive	-
6	Negative	-	-	Positive	Positive	-
7	Negative	Positive	Positive	Positive	-	-
8	Negative	Positive	-	-	-	Positive
9	Negative	Positive	Positive	-	Positive	-
10	Negative	-	-	Positive	Positive	Positive
11	Negative	-	-	-	-	Positive
12	Negative	-	-	-	-	Positive
13	Negative	Positive	Positive	-	-	-
14	Negative	Positive	-	-	Positive	Positive
15	Negative	Positive	-	Positive	-	-