Recovery of paraffin blocks and central archiving. Experiences of the Kiel lymph node registry and the German study group for Hodgkin lymphoma

Central collection of tissue blocks for pathological and translational research is particularly important in rare diseases. Transfer of tissue blocks from primary to central pathology is of crucial importance. We aimed to answer the following questions: Has the transfer of tissue blocks sent for consultation or within clinical trials changed over the last 20 years? What are the reasons for reclaiming tissue blocks by the primary pathology and what actions would convince primary pathologists to leave the blocks in the reference pathology? The first 100 biopsies of each year between 1995 and 2015 (n = 2100), as well as all tissue transfers within therapeutic studies (n = 1405, German Hodgkin Study Group, GHSG) between 1998 and 2015, were analyzed separately for block reclaims using the Department of Pathology database. A questionnaire evaluated the reasons for block reclaiming by the peripheral pathologists. There is a significant increase in block reclaims during the period analyzed among submissions for consultation as well as in clinical trials (linear regression, p = 0.0195 and p = 0.0107). The percentage of block reclaims does not differ between consultations and cases submitted upon request within clinical trials (p = 0.2404, t-test). A survey among pathologies that reclaim the block showed that their willingness to leave the block at the reference center would increase if the compatibility with accreditation guidelines (39.3%), a positive statement from professional associations (25%), or a formal confirmation of availability (53.6%) is provided. In particular, to improve research on rare diseases, it is desirable to point out the compatibility of central archiving in a designated center with accreditation guidelines.