It's rare a pathologist would take a whole brain, but not out of the realm of possibility.

Within BrainNet Europe (BNE, www.brainnet-europe.org), a consortium of 19 European brain banks established by the European Commission, an Ethical Code of Conduct was installed . This Code covers the basic legal rules and bioethical principles involved in brain banking and is based on legislation and guidelines issued by international governmental and non-governmental key organizations, such as the Council of Europe (CoE), the European Commission, the United Nations, the World Medical Association and the World Health Organization and is mostly based on the Recommendation of the Committee of Ministers of the CoE to member states on research on biological materials of human origin (Council of Europe Committee of Ministers, Explanatory Report, 2005, http://conventions.coe.int/Treaty/EN/Reports/Html/195.htm; Recommendation, 2006, https://wcd.coe.int/ViewDoc.jsp?id=977859). In June 2008, all BNE II partners signed this Code of Conduct. This type of self-regulation is hoped in the long run to contribute to uniform and unambiguous European legislation guiding transparent brain banking and to guide new and professionalize existing brain banks.

I love me some voluntary self regulation of checks notes brain collection