"Correlative" just means having a relationship with something else. In medicine, that means that the biopsy correlates with another modality, whether it be imaging studies or physical exam or whatever. "Correlative biopsy" sounds kind of redundant to me. All biopsies are correlative. If they didn't need to correlate with something then they wouldn't do the biopsy. As an example - you would see a mass in the kidney on CT scan. Then you do a biopsy. The biopsy findings should be correlated with the imaging studies. Thus, if the biopsy findings show kidney cancer it correlates. If the biopsy findings show liver tissue then the biopsy doesn't correlate and needs to be redone.