Clinicopathological and mutational characteristics of primary double mutant gastrointestinal stromal tumor: a single center study with review of the literature

Table 2 Immunohistochemical and genetic findings of double primary mutant GISTs

	Immunohistochemistry						Ki−67	KIT/PDGFRA mutation analysis
Case	CD117	CD34	DOG−1	SMA	Desmin	S−100	Ki−67	Mutations	Allelic distribution
1	+	+	+	-	-	-	5–8%	KIT exon 11 p.V559D + exon13 p.K642E	NA
2	+	-	+	+, scattered	-	-	10%	KIT exon 11 W557R + D579del	trans
3	+	+	+	-	-	+, scattered	1%	KIT exon 11 V569_L576del + exon 13 M651L KIT exon 3 L138fs* + exon 13 K642fs*	NA
4	+	ND	-	+, focal	-	-	10%	KIT exon 11 V559A + exon 13 I653fs	NA
5	+	+	+	-	-	-	10–15%	KIT exon 11 V560G + D579A	cis
6	+	+	+	+, scattered	-	-	5–10%	KIT exon 11 V559D + V559G	NA
7	+	+, focal	+	+, focal	-	-	5%	KIT exon 13 K642E + exon 17 S821C	NA
8	+	+	+	-	-	-	5–10%	KIT exon 9 A502_Y503dup + exon 11 W557_V560delinsC	NA

NA, not available;
*The mutations were only present in a proportion of the DNA molecules identified by NGS (AF < 10%).

ISSN: 1471-2407