Table 2. Concordance of FISH and RT–PCR positivity according to EWSR1-rearranged neoplasm subtype.

		Positive FISH; Positive RT–PCR		Positive FISH; Negative RT–PCR		Positive FISH; Failed RT–PCR		Positive FISH; RT–PCR ND		Negative FISH; Positive RT–PCR		Negative FISH; Negative RT–PCR		Negative FISH; Failed RT–PCR		Negative FISH; RT–PCR ND
Histology	Samples tested	n	%	n	%	n	%	n	%	n	%	n	%	n	%	n	%
Ewing sarcoma	109	45	41.3	15	13.8	12	11.0	17	15.6	4	3.7	4	3.7	5	4.6	5	4.6
DRSCT	22	9	40.9	0	0.0	3	13.6	7	31.8	2	9.1	1	4.5	0	0.0	0	0.0
Myxoid LPS (FISH and RT–PCR comparison not possible due to lack of commercial EWSR1-DDIT3 primers)	24	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
EMC	41	14	34.1	7	17.1	1	2.4	2	4.9	0	0.0	11	26.8	1	2.4	4	9.8
AFH	20	9	45.0	2	10.0	0	0.0	1	5.0	4	20.0	3	15.0	0	0.0	0	0.0
CCS	33	17	51.5	5	15.2	3	9.1	4	12.1	0	0.0	3	9.1	0	0.0	1	0.03
CCSLGT	5	4	80.0	0	0.0	0	0.0	0	0.0	1	20.0	0	0.0	0	0.0	0	0.0
PPMS	2	1	50.0	0	0.0	0	0.0	0	0.0	0	0.0	0	0.0	1	50.0	0	0.0
Myoepithelial neoplasm	42	0	0.0	8	19.0	3	7.1	2	4.8	0	0.0	7	16.7	2	4.8	17	40.5
LGFMS and SEF	19	0	0.0	1	5.3	1	5.3	3	15.8	6	31.6	1	5.3	1	5.3	6	31.6

Abbreviations: AFH=angiomatoid fibrous histiocytoma; CCS=clear cell sarcoma; CCSLGT=clear cell sarcoma-like tumour of the gastrointestinal tract; DSRCT=desmoplastic small round cell tumour; EMC=extraskeletal myxoid chondrosarcoma; LGFMS=low-grade fibromyxoid sarcoma; LPS=liposarcoma; NA=not applicable; ND=not done; PPMS=primary pulmonary myxoid sarcoma; RT–PCR=reverse transcription–PCR; SEF=sclerosing epithelioid fibrosarcoma.