Table 4. Characteristics of FISH-positive metaplastic breast carcinomas.

Case no.	Tumor Histology	EGFR*	EGFR FISH†	KIT*	CK 5/6‡	p63‡	ER‡	PR‡	HER2 FISH†
32	Spindle cell	3+	Aneusomy	-	+	+	-	-	-
34	Spindle cell	3+	Amplification	-	-	+	-	-	-
8	Glandular and spindle cell	3+	Aneusomy	-	-	+	-	-	-
3§	Glandular and spindle cell	3+	Aneusomy	-	+	+	-	-	-
27	Glandular with squamous and spindle cell	3+	Aneusomy	-	+	+	-	-	-
33	Glandular with squamous and chondroid	2+	Aneusomy	-	+	-	-	-	-
16	Squamous and spindle cell	1+	Aneusomy	-	+	+	-	-	-
23	Spindle cell and chondroid	2+	Aneusomy	+	+	-	-	-	-

NOTE: No FISH-positive tumors had EGFR (exons 18, 19, and 21) or KIT (exons 9, 11, 13, and 17) activating mutations.

^*As determined by immunohistochemistry of sections from tumor blocks. EGFR staining was scored based on intensity from 0 to 3+, with overexpression defined as intensity of 2+ or 3+.

^†As determined by FISH of tissue microarray sections. “EGFR FISH”, determination of FISH-positivity (aneusomy with ≥40% of cells having ≥4 copies of EGFR or EGFR amplification); “HER2 FISH,” determination of Her-2/neu amplification.

^‡As determined by immunohistochemistry of tissue microarray sections.

^§Recurrent disease; all other cases were primaries.