pulmonary disorders
Mediastinal Masses
Diagnosis of Mediastinal Masses
Chest x-ray CT and sometimes MRI Sometimes tissue examination Mediastinal masses are most often incidentally discovered on chest x-ray or other imaging tests during an examination for chest symptoms. Additional diagnostic testing, usually imaging and biopsy, is indicated to determine etiology. CT with IV contrast is the most valuable imaging technique. With thoracic CT, normal variants and benign tumors, such as fat- and fluid-filled cysts, can be distinguished from other processes. An MRI is done if the structure is cystic. MRI may be useful in determining whether the mass is compressing or invading adjacent structures. A definitive diagnosis can be obtained for many mediastinal masses with needle aspiration or Transthoracic Needle Biopsy . Fine-needle aspiration techniques usually suffice for carcinomatous lesions, but a cutting-needle biopsy should be done to provide sufficient tissue for diagnostic analysis whenever lymphoma, thymoma, or a neural mass is suspected. If ectopic thyroid tissue is considered a cause, thyroid-stimulating hormone is measured. Surgical excision is done when there is high suspicion of malignancy based on results of imaging or other tests and when complete resection can be achieved. 