A 62-year-old patient with lung cancer was referred to our institution. As part of the work-up for staging, a thoracic CT was performed demonstrating a particular lesion.
Computed tomographic images of a typical sternal foramen. The axial and sagittal planes (Figure 1 and 2) show the close contact to vital structures.
Sternal perforation is an anatomic variation whose frequency varies from 1 to 10% in different populations. Typical position is at the caudal parts of the corpus sterni. Detailed studies have shown that this anomaly is related to highly specific patterns of ossification of the sternum. Embryologically, it corresponds to an anomaly of the process of segmentation that cleaves skeletal precursors into separate elements.
The sternum originally consists of two cartilaginous bars, situated one on either side of the median plane. These bars fuse along the middle line to form the cartilaginous sternum which is ossified from six centres: one for the manubrium, four for the body, and one for the xiphoid process. The centres make their appearance at the upper parts of the segments, and proceed gradually downward. Occasionally some of the segments are formed from more than one centre, the number and position of which vary. The first piece may have two, three, or even six centres. When two are present, they are generally situated one above the other, the upper being the larger; the second piece has seldom more than one; the third, fourth, and fifth pieces are often formed from two centres placed laterally, the irregular union of which explains the rare occurrence of the sternal foramen or of the vertical fissure which occasionally intersects this part of the bone constituting the malformation known as fissura sterni. More rarely still the upper end of the sternum may be divided by a fissure.
It is important to be aware about this anatomic variant, since it carries the risk of life-threatening complications like pneumothorax or even pericardial/cardial punction during sternal biopsy or acupuncture. Moreover, it can mimic an osteolytic lesion, particularly in oncological patients as this one.
Sternal perforation/foramen
On the chest CT (coronal, sagittal, and axial images), there is a circular or nearly circular radiolucent area within the sternum, located near the sternal body, presenting as a clearly demarcated local bone defect-like appearance. The lesion margins are distinct and regular, with no obvious signs of bone destruction or erosive changes. No notable swelling or mass effect is observed in the surrounding soft tissue, and no clear calcification is identified.
Based on the imaging characteristics, the lesion is well-defined with regular margins, and the patient has no prominent local pain or swelling. Given the patient’s history of pulmonary tumor, differential diagnosis with metastatic osteolytic lesions should be considered.
Considering the patient’s history of lung tumor, the imaging findings, and the typical morphological characteristics of a sternal foramen, the most likely diagnosis is: Sternal Foramen (Sternal Foramen/Perforation), a congenital anatomical variation.
This structure can resemble a pathological osteolytic lesion on imaging, but its regular shape, sharp borders, and the absence of local soft-tissue infiltration often indicate an anatomical variant. If uncertainty remains, further evaluation using CT multiplanar reconstruction or other ancillary tests (such as MRI or bone scan) may be considered to exclude metastatic disease.
Although a sternal foramen itself does not typically limit regular exercise, rehabilitation training should be tailored to the patient’s overall health status and underlying cardiopulmonary function, especially given the history of lung cancer.
This report provides a preliminary academic analysis based on the available imaging data and clinical information. It does not constitute a definitive medical diagnosis or treatment advice. Specific diagnoses and treatment plans should be determined by combining the patient’s overall clinical assessment and findings from an in-person professional consultation. If you have any questions, please consult a specialist promptly.
Sternal perforation/foramen
