Case #4

Case #2

• Large right posterior mediastinal mass measuring 10 cm in craniocaudal span with mass effect on the trachea
• No acute airspace opacification or edema
• No pleural effusion or pneumothorax
• Heart size within normal limits

• Posterior mediastinal mass (thyroid goiter)

• It is important to try to separate mediastinal masses based on location in the anterior, middle, or posterior mediastinum
• Thyroid goiters can extend into the anterior or posterior aspect of the superior mediastinum
• This case is a good example of the cervicothoracic sign, which indicates that if a mediastinal mass has clearly defined margins above the level of the clavicles, it must be in the posterior mediastinum (the anterior and middle mediastinum does not extend above the level of the clavicles)
• A recent publication by the International Thymic Malignancy Interest Group (ITMIG) defines the three mediastinal compartments as prevascular (bounded posteriorly by the pericardium), visceral (bounded anteriorly by the pericardium and posteriorly by an imaginary line drawn through each thoracic vertebral body 1 cm from its anterior margin), and paravertebral
• Think about the following categories with posterior (paravertebral) mediastinal masses:
  • Neurogenic abnormalities: neurogenic tumors (nerve sheath, parasympathetic, sympathetic), neurenteric cysts, meningocele
  • Bone tumors/metastases
  • Infection – e.g. paraspinal abscess
  • Trauma – e.g. hematoma
  • Extramedullary hematopoiesis
• This case turned out to be a large thyroid goiter (see CT image below).

Images