A sternal foramen is a round or ovoid congenital bony defect that results from incomplete fusion of the sternal ossification centres. The estimated prevalence is 4.5%. It is typically asymptomatic and of no clinical significance, except in the setting of sternal acupuncture due to the risk of pericardial puncture and tamponade. There have been two such reported cases in the literature, one of them fatal.

Yekeler E, et al. Frequency of Sternal Variations and Anomalies Evaluated by MDCT. American Journal of Roentgenology 2006;186:956-960
Kirshgatterer A, et al. Cardiac Tamponade Following Acupuncture. Chest 2000;117:1510-1511

Credit: Dr Donna D’Souza