A keyhole-shaped sternal defect in an ancient human skeleton

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.