Scientific analysis of a calcified object from a post-medieval burial in Vienna, Austria

Abstract

Calcifications commonly occur in association with soft tissue inflammation. However, they are not often discussed in palaeopathological literature, frequently due to problems of identification and diagnosis. We present a calcified object (40 × 27 × 27 cm) found with a middle-aged male from a post-medieval cemetery in Vienna. It was not recognized during excavation, thus its anatomical location within the body remains unknown.

The object was subject to X-ray, SEM and CT scanning and compared to historic pathological objects held in the collection of the Natural History Museum Vienna. Two of closest resemblance, a thyroid adenoma and goitre were subject to similar analytical techniques for comparison. Despite similarities between all objects, the structure of the object most closely conforms to a thyroid tumor. Nevertheless, due to similar pathophysiological pathways and biochemical composition of calcified soft tissue, a secure identification outside of its anatomical context is not possible.

The research further highlights the fact that recognition of such objects during excavation is crucial for a more conclusive diagnosis. Historic medical records indicate that they were common and might therefore be expected to frequently occur in cemeteries. Consequently, an increasing the dataset of calcifications would also aid in extending the knowledge about diseases in past human populations.

Introduction

Despite the relatively common occurrence of pathological calcifications in modern clinical contexts (Black and Kanat, 1985), in the palaeopathological literature such objects are only occasionally reported for archaeological human skeletal remains. In addition, in most cases the identification of these structures remains tentative. Calcifications in the human body can result from a large number of different pathological conditions including vascular, infectious, inflammatory, metabolic, and neoplastic entities (see Table 1) and can occur in virtually all anatomical regions of the body (Banks et al., 2005; Bohndorf et al., 2006: 288). Patho-physiologically, they are classified into organic concretions and calcifications of pathological lesions in soft tissue. Soft tissue calcifications are further subdivided into dystrophic, accounting for 93–95% of all observed cases, and metastatic, which are generally rare (Banks et al., 2005, Kumar et al., 2013a). Metastatic forms occur in living tissue and are always related to an imbalance of the mineral metabolism, whereby dystrophic forms arise from necrotic tissue and do not involve any metabolic changes (Bohndorf et al., 2006: 288). While metastatic calcifications are usually associated with significant morbidity and mortality, dystrophic calcifications are often asymptomatic and relatively common. In a large-scale roentgenological study carried out in the central US in the 1940s, 63% of patients were found to have calcifications in the thoracic cavity resulting from atherosclerosis, silicosis or infectious diseases such as histoplasmosis, tuberculosis or other parasitic infections (Felson, 1969).

In the palaeopathological literature, several different types of calcified structures have been reported dating back as far as the Neolithic period, including parasite cysts (e.g. Perry et al., 2008, Waters-Rist et al., 2014), tumorous calcifications (e.g. Strouhal and Jungwirth, 1977, Komar and Buikstra, 2003, Quintelier, 2009), vascular calcifications (Binder and Roberts, 2014) as well as organic concretions (e.g. Özdemir et al., 2013). However, specific identifications are often impossible due to the wide range of potential underlying causes and unspecific morphology of the objects. Furthermore the lesions develop through similar underlying pathophysiological mechanisms and the biochemical composition of most soft tissue calcifications is indistinguishable from bone (Baud and Kramar, 1991). This paper reports the finding of an ovoid calcified object (40 × 27 × 27 mm, Fig. 1) of unknown origin in the burial of a middle adult male individual (Fig. 2) from the post-medieval cemetery of St.-Bartholomäus-Platz in Vienna, Austria.