Histological investigation of a bone core biopsy of the Tyrolean Iceman

Abstract

We report here on the morphological findings obtained in a small trephination core biopsy from the iliac crest of the Tyrolean Iceman (“Ötzi”). The approx. 1 cm long biopsy showed excellently conserved spongy bone and was divided prior to analysis into two parts for subsequent histological analysis following either careful decalcification or embedding into epoxy resin. Both techniques showed a typical network of bone trabeculas with empty osteocytic lacunae. Surprisingly, focally the residues of a delicate network of bone marrow connective tissue fibers were seen suggesting excellent conservation, although there were no residues of the cellular compartment of the marrow. There was no evidence for fibrosis. Resin embedded sections showed bone trabeculas with occasional small superficial hypomineralization bands such as seen in mild osteomalacia. The center of trabeculas, however, appeared regularly mineralized. There was no evidence for bone apposition, enhanced osteoclasia or structurally immature bone matrix. In conclusion, we detected signs of a very mild hypomineralization of few bone trabeculas. Since the conservation of the sample was so excellently well that even tiny marrow fibers were evident, we reject the assumption of postmortal artefactual demineralization and suggest mild osteomalazia in the individual during lifetime. This would be consistent with previous reports indicating Ötzi to have suffered from intestinal parasitosis which is a frequent cause of (mild) osteomalacia. In addition, we have no evidence that the Iceman suffered from other generalized metabolic diseases affecting bone.