Differential for an anterosuperior mediastinal mass

An anterosuperior mediastinal mass can be caused by neoplastic and non-neoplastic pathology. As their name suggests, they are confined to the anterior mediastinum, that portion of the mediastinum anterior to the pericardium and below the level of the clavicles. 

The differential diagnosis for an anterior mediastinal mass includes:

• thymus
  • thymoma: most common primary neoplasm of the anterosuperior mediastinum
  • invasive thymoma
  • thymic carcinoma
  • thymolipoma/thymoliposarcoma
  • thymic cyst
  • thymic hyperplasia
  • thymic carcinoid
• thyroid and parathyroid
  • thyroid neoplasms
  • thyroid goiter
  • parathyroid neoplasms
• lymphoma
  • Hodgkin lymphoma 
  • non-Hodgkin lymphoma
• germ cell tumors
  • mediastinal teratoma
    • mature: 75% of mediastinal germ cell tumors
    • immature
    • teratocarcinoma (malignant teratoma)
  • mediastinal seminoma
  • mediastinal embryonal cell carcinoma
  • mediastinal yolk sac tumor
  • mediastinal choriocarcinoma
  • mediastinal mixed cell type germ cell tumor
• thoracic aortic aneurysm

Mnemonic

• the 5 Ts