What Is a Lung Granuloma?

A lung granuloma is an area of inflamed tissue that is often the result of an infection, states Mayo Clinic. Granulomas do not usually cause symptoms. Lung granulomas are typically found when a chest X-ray or another imaging test is performed.

In the United States, the most frequent cause of lung granulomas is a fungal infection called histoplasmosis, native to the upper Midwest and Ohio Valley, states Mayo Clinic. Granulomas can appear similar to cancer on a chest X-ray. As they calcify over time, granulomas appear more similar to bone.

Although granulomas are most often associated with fungal infections, they can also be a symptom of diseases such as sarcoidosis, Wegener's granulomatosis and talc granulomatosis. These diseases are uncommon. Talc granulomatosis is usually caused when tablets that are meant for oral delivery are injected, according to PubMed.

Sarcoidosis is an autoimmune disease that is serious but rarely fatal, according to WebMD. Sarcoidosis primarily affects the lungs and lymph nodes and can cause deterioration of the lungs if untreated. Wegener's granulomatosis is a rare disease in which blood vessels become inflamed, according to Mayo Clinic. With Wegener's granulomatosis, the inflamed blood vessels damage organs by restricting the flow of blood to them. While potentially fatal, the disease is treatable when diagnosed early.