Differential Diagnosis for a 30-year-old Male with Substernal Painless Pronounced Sternal Lump after Skateboarding Trauma

• Single Most Likely Diagnosis
  • Sternal Fracture or Contusion: Given the history of trauma to the rib cage from skateboarding, a sternal fracture or contusion is highly plausible. The presence of a pronounced sternal lump supports this diagnosis, as it could represent a hematoma or callus formation at the site of the fracture.
• Other Likely Diagnoses
  • Costochondritis: This condition, which involves inflammation of the cartilage that connects the ribs to the sternum, could be exacerbated by the trauma, leading to pain and swelling in the sternal area.
  • Sternal Osteomyelitis: Although less common, if the trauma led to an open wound or if there was a pre-existing condition, an infection of the sternum could occur, presenting with swelling and possibly pain.
• Do Not Miss Diagnoses
  • Myocardial Contusion: Although the patient is described as having a painless lump, the mechanism of injury could also have affected the heart, leading to a myocardial contusion, which is a serious condition that requires immediate medical attention.
  • Pulmonary Contusion or Pneumothorax: The trauma could also have injured the lungs, leading to a contusion or pneumothorax, both of which are life-threatening conditions that need prompt diagnosis and treatment.
• Rare Diagnoses
  • Sternal Tumor: Although rare, a tumor of the sternum could present as a lump. The recent trauma might not be directly related to the lump but could have drawn attention to a pre-existing condition.
  • Xiphoid Process Abnormalities: Abnormalities of the xiphoid process, such as a bony growth or inflammation, could present as a lump in the lower part of the sternum. These conditions are less common and might not be directly related to the trauma.