COVID-19 can cause mediastinal lymphadenopathy, but it is not considered a typical finding on chest CT scans of patients infected by COVID-19
COVID-19 can cause mediastinal lymphadenopathy, but it is not considered a typical finding on chest CT scans of patients infected by COVID-19.
A study published in The Lancet (November, 2020) showed the presence of mediastinal lymphadenopathy in critically ill patients with COVID-19. However, another review article (April, 2021) that analyzed multiple studies on mediastinal lymphadenopathy found that mediastinal lymphadenopathy was seen in around 0%-66% of COVID-19 cases.
The condition was not significantly associated with any gender, age or age group, or cancer history and did not increase the need for noninvasive ventilation and ICU admission in patients with COVID-19. There was no difference in the length of hospital stay and pattern of lab results in patients with COVID-19 with and without mediastinal lymphadenopathy.
What is mediastinal lymphadenopathy?
Mediastinal lymphadenopathy refers to enlarged lymph nodes in the mediastinum, which is located between the lungs and contains all primary tissues and organs of the chest except the lungs:
- Heart
- Thymus gland
- Portions of the esophagus and trachea
- Cardiac nerves
- Lymph nodes of the central chest
Lymph nodes are small bean-shaped structures that play a vital role in the body's immune system. They filter substances that travel through the lymphatic fluid and contain lymphocytes, which are white blood cells that help the body fight infection and disease.
What causes mediastinal lymphadenopathy?
Mediastinal lymphadenopathy generally indicates a problem with the lungs. The most common causes include
- Lung cancer
- Lymphoma (cancer that begins in the lymphocytes)
- Anthracosis or Miner’s lung (lung condition caused by the accumulation of carbon in the lungs due to repeated exposure to air pollution or inhalation of smoke or coal dust particles)
- Chronic obstructive pulmonary disease (COPD, a chronic inflammatory lung disease that progresses and obstructs the airflow from the lungs)
- Acute lymphoblastic leukemia (cancer of the blood and bone marrow)
- Coccidioidomycosis or valley fever (infection caused by the fungus Coccidioides, which is known to live in the soil)
- Cystic fibrosis (genetic condition that damages multiple organs in the body, most commonly the lungs and organs of the digestive system)
- Esophageal cancer
- Histoplasmosis (infection caused by the fungus Histoplasma)
- Sarcoidosis (inflammatory disease that affects multiple organs in the body, mostly the lungs and lymph glands)
- Tuberculosis
From a global perspective, mediastinal lymphadenopathy is primarily associated with tuberculosis given the high rate of infection (10 million per year). In the United States, it is most commonly associated with lung cancer and COPD.
How is mediastinal lymphadenopathy diagnosed?
Mediastinoscopy
Mediastinal lymphadenopathy can be detected in chest CT scans. To confirm the cause, mediastinoscopy with biopsy may be recommended. This is a minor surgical procedure that involves the insertion of a thin, flexible tube-like instrument (mediastinoscope) into the middle part of the chest to obtain a sample of one or multiple lymph nodes. The sample is then sent to a lab for examination under a microscope.
Fine needle aspiration cytology (FNAC)
Alternatively, a less invasive procedure called fine-needle aspiration cytology (FNAC) may be recommended. This involves the insertion of a long needle through the chest cavity into a lymph node to extract cells.