Mediastinal lymphadenopathy is an enlargement of the lymph nodes located in the mediastinal part of the chest, the area in the middle that separates the lungs. The enlargement is typically diagnosed through a chest x-ray. Mediastinal lymphadenopathy is not a disease itself, but a symptom of another disease. Causes of include infections, several types of cancer, and other diseases. Treatment depends on the underlying cause.
Lymph nodes are small round or oval shaped masses made up of lymph tissue surrounded by connective tissue. They are located in many places throughout the body and play a major role in the immune system by storing cells that can trap cancer cells or bacteria. Enlarged lymph nodes typically indicate the presence of infection, cancer, or other diseases.
Several different types of infectious diseases can cause mediastinal lymphadenopathy. The two most common types are tuberculosis and fungal infections, including histoplasmosis and coccidioidomycosis. Tuberculosis is an infectious bacterial disease that primarily infects the lungs, but may spread to other organs. Histoplasmosis is caused by breathing in the Histoplasma capsulatum fungus in soil or bird droppings and primarily affects farmers, construction workers, or occupations that involve close contact with sources of the fungus. Coccidioidomycosis is also caused by fungus found in the soil, and is most common in the Southwestern United States, Central America and South America.
Lung cancer is the main type of cancer that can cause mediastinal lymphadenopathy, and the disease typically spreads to the lymph nodes before other parts of the body. Once lung cancer is diagnosed, additional imaging tests are used to determine if the cancer has spread into the lymph nodes. This can also help determine how advanced the cancer is. Breast cancer and cancer of the esophagus can also cause this condition.
Mediastinal lymphadenopathy can also be present in several types of less common diseases, including Castleman’s disease and Wegener’s granulomatosis. Castleman’s disease is a rare disorder with an unknown cause that affects the lymph nodes and immune system. Wegener’s granulomatosis, also rare, constricts the blood vessels and produces granuloma, a type of inflammatory tissue that can destroy normal tissue.
Once the underlying cause of the condition is treated, the lymph nodes should return to their normal size. For bacterial and fungal infections, antibiotics or anti-fungal medications are typically prescribed. When the lymph node itself is diseased, as in the case of cancer or Castleman’s disease, surgical removal of the node may be required.