The human body’s cells and tissues become inflamed for various reasons, leading to the formation of histiocyte clusters in the affected area. These clusters then create nodules called granulomas, which can form in the lungs, liver, eyes, and skin. Nodules that form in the lungs are called lung granulomas, and they can be soft at first but may become hard as they grow. These nodules are non-cancerous and, in most cases, do not present symptoms.

Causes of lung granulomas
Doctors have identified many causes that lead to the formation of lung granulomas. Here are some of the main causes:

Infections
The following infections can cause lung granulomas:

• Tuberculosis
• Fungal infections
• Bacterial infections
• Parasital infections

Non-infectious diseases
Some of the non-infections and other diseases that lead to lung granulomas include:

• Aspiration pneumonia
• Churg-Strauss syndrome
• Granulomatosis with polyangiitis
• Sarcoidosis
• Crohn’s disease
• Chronic granulomatous disease

Autoimmune diseases
Autoimmune diseases occur when the immune system mistakenly attacks the healthy cells, leading to lung granuloma. Some such autoimmune diseases include:

• Rheumatoid Arthritis
• Sjogren’s Syndrome
• Inflammatory Bowel Disease

Leukemia
A person’s body affected by leukemia can produce more lymphocytes – this condition is called lymphomatoid granulomatosis, which can lead to lung granuloma formation.

Immunodeficiency
When the body does not produce or have some of the components of the immune system, a person is said to have immunodeficiency.

External and environmental causes
Apart from pre-existing diseases, lung granulomas are also caused by environmental factors that result in health problems. They include:

• Berylliosis
  Beryllium is used to manufacture electronics and auto components. Exposure to beryllium can lead to skin and respiratory issues as well as lung granulomas.
• Hypersensitivity pneumonitis
  Exposure to specific allergies can inflame the lungs and cause a reaction. The allergens can be mold, fungi, or toxins like chemicals and dyes.
• Long-term exposure to specific metals
  Inhaling harmful metals at the workplace can cause inflammation. Iron, copper, silicon, cobalt, and aluminum are among the metals that can cause lung granulomas.

Risk factors for lung granulomas
The important risk factors for lung granuloma are:

• Age above 55
• Female
• Family history of Sarcoidosis
• Weak immune system
• Exposure to toxins, chemicals, specific metals, and mold may cause inflammation in the lungs
• Use of some HIV prescription treatments and monoclonal antibodies
• People who have a history of infections or diseases

Types of lung granulomas
Lung Granulomas are classified based on their cause. The different types of lung granuloma include:

• Infectious granulomas
  Various bacterial infections like Tuberculosis and other fungal infections cause this type of lung granulomas.
• Non-infectious granulomas
  Diseases like Sarcoidosis are often the cause of this type of non-infectious lung granulomas.
• Foreign body granulomas
  It is a rare type of Granuloma caused by foreign particles in the pulmonary capillaries – the smallest blood vessels in the lungs.
• Malignant granulomas
  Though lung granulomas are by nature non-cancerous, some of them associated with lung cancer can become malignant, requiring immediate medical intervention.
• Radiation-induced granulomas
  These types of lung granulomas develop as a side effect of radiation therapy applied to the chest region.

Signs of lung granulomas
The signs of lung granulomas mimic the underlying disease or condition causing it.

• A person diagnosed with Sarcoidosis may experience wheezing, shortness of breath, or a dry cough.
• A person with Histoplasmosis infection may experience fever, chest pain, red bumps in the lower part of their legs, and a dry cough.
• A person with Tuberculosis may have a chronic cough, chest pain, or a bloody phlegm.

Diagnosis of lung granulomas
Since there are no specific symptoms of lung granulomas, and the symptoms mimic the signs of the underlying disease, in most cases, the condition is diagnosed during routine medical examinations or screening or examinations for other conditions based on their existing symptoms.

Physical exams
A doctor may conduct a complete physical examination to understand the patient’s health history and determine if there is any infection that may lead to the condition.

Blood exams
Doctors recommend blood exams to check for bacterial or fungal infections that could be causing unusual symptoms. They may also recommend common tests for diagnosing lung granulomas, such as complete blood count, serology, and tuberculosis exams.

Imaging tests
In most cases, doctors may notice white spots in the lungs in an X-ray or a CT scan and then recommend further exams to ascertain whether they are lung granulomas. Once they notice the granulomas, they may recommend additional imaging tests to confirm whether the nodules are cancerous.

Biopsy
Doctors may also conduct a biopsy to check if the nodules are malignant or benign. The common procedures used to conduct a biopsy, which removes a piece of the Granuloma for examination, include:

• Bronchoscopy
• Needle biopsy
• Surgical biopsy

Treatment of lung granulomas
There is no specific treatment for lung granulomas. Doctors will treat the underlying cause that led to the nodule formation. If the cause is Sarcoidosis, they will treat the condition. if an inflammatory disease causes it, they will prescribe anti-inflammatory treatments. If the lung granulomas are caused by allergens and metals, along with treatment, doctors may recommend avoiding exposure to the metals or toxins that caused the nodules. If the lung granulomas are found to be cancerous, the treatment prescribed may be based on the stage and spread of the cancer.