BC here stands for breast cancer ? If that was the case often the clinical and radiological findings might be significant and biopsy if more for confirmation on paper and often IHC is done along with biopsy because IHC plays a major role in further decision of treatment ...

The specimen taken by biopsy is same as that used for IHC , no need of separate procedure for that . And since the tumor may be more likely to be significant doctor may have written IHC along with it so that you won’t be having any delay for getting treatment . If the biopsy report are negative then also sometimes IHC may be warranted if the lesion is suspicious.

Hi     Generally IHC done after biopsy only but if the lesion is highly suggestive of malignancy clinically and on imaging studies one can go for ihc and biopsy simultaneously