What is the Role of the Tissue Review Committee of Medical Staff?

California and many other states require that the medical staff establish a tissue review committee. (CCR 22 section 71503)  But what exactly does the tissue review committee do?

The tissue committee's function is to further medical staff education and self-discipline. The work of the tissue committee is not directly concerned with a particular patient's medical problem, or what should be done about it.

It is, instead, a postsurgical activity relating to the tissue removed. Study and comparison is made of the preoperative diagnosis with both the postoperative diagnosis and the pathologist's report. 

Source: Tissue Committee of a Hospital Medical Staff A Report of the Medical Review
And Advisory Board (California Medicine)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1574531/pdf/califmed00172-0108.pdf