Table 1.

Discordant ER results

N	Local ER testing result	ER result after revision of original slide	TMA and whole-slide ER result	Conclusion	Reason for discordance
1	Negative	Negative	Positive	False negative	IHC error
3	Negative	Positive	Positive	False negative	Observer error
2	Positive	Positive	Negative	False positive	IHC error
9	Positive	Negative	Negative	False positive	Observer error
1	Positive	Unknown	Negative	False positive	Unknown