Mediastinal Mass – Thymoma
Mediastinal Masses are benign or cancerous growths that form in the area of the chest that is between your lungs. The area, the mediastinum, is surrounded by the breastbone, the spine and the lungs. The mediastinum contains the heart, aorta, esophagus, thymus and trachea. Mediastinal Masses are divided into those that are located in the anterior, middle or posterior of the mediastinum.
Some causes of Anterior Mediastinal Masses in adults are:
- Thyroid Tumor
- Thymoma (associated with myasthenia gravis)
- Parathyroid Tumor
- Angiomatous Tumor
- Morgagni Hernia
- Pericardial Cyst
Some causes of Middle Mediastinal Masses in adults are:
- Bronchogenic Cyst
- Pleuropericardial Cysts
- Bronchogenic Tumor
- Esophageal Duplication Cyst
- Lymph Node Hyperplasia
- Vascular Masses
Some causes of Posterior Mediastinal Masses in adults are:
- Enteric Cyst
- Esophageal Tumor
- Bronchogenic Tumor
- Esophageal Diverticula
- Neurogenic Tumor (schwannoma and neurofibroma)
A lot of Mediastinal Masses do not have symptoms. When there are symptoms, the most common is weight loss. Lymphomas may manifest with a fever and weight loss. Large Anterior Mediastinal Masses may cause shortness of breath when lying down with your face facing the ceiling. Middle Mediastinum may compress blood vessels or airways, causing airway obstruction. Posterior Mediastinum may cause encroachment on the esophagus, making it difficult and/or painful to swallow.
Chest x-rays, CT scans and sometimes tissue examinations are used to diagnose Mediastinal Masses.
Mediastinal Masses are most often discovered on a chest x-ray or other imaging tests during an examination for chest symptoms. Additional diagnostic testing, usually imaging and biopsy, is indicated to determine the cause.
CT scan with IV contrast can be obtained for many Mediastinal Masses with needle biopsy. Fine-needle biopsy techniques usually suffice for cancer in the tissue protecting various parts of the body, but a cutting needle biopsy should be done whenever Lymphoma, Thymoma, or a Neural Mass is suspected. If Ectopic Thyroid tissue is considered, Thyroid- stimulating hormone is measured.
In adults, Hodgkin and non-Hodgkin are the most common anterior lesions, lymph node enlargement and vascular masses are the most common middle lesions, and neurogentic tumors and esophageal abnormalities are the most common posterior lesions.