A keyhole-shaped sternal defect in an ancient human skeleton

Abstract

We observed a sternal foramen contiguous with a small sternal cleft in a human skeleton coming from North-Eastern Italy and dating back to between the sixteenth and seventeenth century AD. Both of these types of anomalies result from a defective midline fusion of the developing sternum. Sternal foramen is a relatively common bony defect that usually comes to light as an incidental finding. Sternal cleft is a rarer morphological anomaly that can have a wide spectrum of clinical manifestations and outcomes, depending on the extent of the bony defect as well as on the presence and severity of other abnormalities. The coexistence of a sternal foramen and a sternal cleft has very rarely been described in the literature. We report here one such unusual association and discuss its potential practical implications. In most cases, sternal foramina and small sternal clefts are clinically uneventful; yet, lack of awareness about the existence of these subtle anatomical variations can sometimes lead to misinterpretation of radiological and pathological findings or make sternal biopsy and acupuncture unsafe.

Frequency of sternal foramen evaluated by MDCT: a minor variation of great relevance

“…Sternal foramen is a relatively common developmental variation that usually occurs as a small (diameter: range 2-16 mm, mean 6.5 mm), round or oval-shaped, solitary lesion [2,22,30]. The bony defect is most often located in the xiphoid process or in the lower third of the sternal body: multiple foramina and foramina in the manubrium are very unusual [6,9,24,30].…”

“…Knowledge of radiologic appearances of sternal variations and anomalies is useful so as to not confuse those with pathologic conditions [22,30].…”

“…The sternum is one of the skeleton parts with most frequent variation on images appearances [14,30] or autopsy series [2,6,8,22].…”

“…The largest series evaluating sternal variations and anomalies were based on macroscopic [2,6,22] and radiographic [17] appearances of the sternum in autopsy populations [2,8]. The frequencies of sternal variations in living subjects have been described based on their radiograph [14], helical CT [23,26], or MRI appearances [1,10,27].…”

“…Thus, radiologists and pathologists should be aware of the existence of these anatomical variations of the sternum as well as be familiar with their imaging features, in order to avoid diagnosis uncertainties or iatrogenic lesions [22,30]. Sternal clefts could be misinterpreted as traumatic fractures, whereas a sternal foramen can mistakenly suggest an osteolytic lesion [21].…”