Presented at: 23rd Paleopathology Association European Meeting, Vilnius, Lituânia, 25-29 Agosto. Paleopathology Association European (Vilnius, Lituânia) Disease identification in paleopathology relies on the exercise of differential diagnosis, and interpretation. Only a few diseases leave macroscopic pathognomonic traits in bone, and even in cases where microscopic, biochemical and biomolecular analyses are used, diagnosis is invariably inconclusive. Additionally, bone response to a variety of etiologies tends to be homogenous, with mosaic pattern(s) of bone formation and destruction. Therefore, access to pathological cases from human remains of Documented Human Osteological Collections (DHOC) is an exceptional approach. The access to biographical data of the individuals incorporated into the DHOC includes the cause of death, ancestry, sex, age, clinical data and other information akin to clinical data allowing for the possibility of hypothesis-driven research in which bones changes correlate with causes of death - hence providing tested and informed differential diagnosis. In this sense, DHOC may be viewed as a biobank equivalent, i.e. biorepository that stores biological samples for research in the identification of bone changes related to diseases associated with clinical and personal data. This paper will explore known cases of diseases’ diagnoses, such as lepra, neoplasias, tuberculosis, syphilis, and diffuse idiopathic skeletal hyperostosis that have used DHOC as diagnostic testing grounds, to explore bone changes and methodological advancements. The paper also introduces the idea of DHOC as biobanks dedicated to the study of rare diseases, as rarely reposted diseases, in paleopathology. Keywords: Health, biorepository, biobanks, DHOC, differential diagnosis

Funding: FCT, Reference: 2020.01014.CEECIND