Nodules could either be malignant (cancerous) or benign (noncancerous). There are many causes of benign pulmonary nodules which are often the result of inflammation in the lung due to an infection or disease producing inflammation in the body. The nodule may still be in an active process or they could be the result of scar tissue formation related to prior inflammation. Nodules could also be due to benign developmental lesions.
- Infections— Examples are mycobacterium such as mycobacterium tuberculosis or mycobacterium avium intracellulare, and fungal infections such as aspergillosis, histoplasmosis, coccidiomycosis, and cryptococcosis.These nodules are usually not active in nature.
Inflammation as a result of infections can form granulomas which are a small clump of cells that form when lung tissue becomes inflamed. - Noninfectious causes of benign inflammatory lung nodules—Disorders such as sarcoidosis, granulomatosis with polyangiitis (GPA), and rheumatoid arthritis.
- Neoplasms—Abnormal growths that may be either benign or malignant.Types of benign neoplasms include:
- Fibroma – a lump of fibrous connective tissue
- Hamartoma – an abnormal grouping of normal tissues
- Neurofibroma – a lump made up of nerve tissue
- Blastoma – a growth made up of immature cells
- Types of malignant tumors include:
- Lung cancer
- Lymphoma – a growth containing lymphoid tissue
- Carcinoid – a small, slow-growing cancerous tumor
- Sarcoma – a tumor consisting of connective tissue
- Metastatic tumors – tumors that have spread to the lungs from cancer in another part of the body
The symptoms associated with pulmonary nodules are usually not detectable. If any are present, they would be associated with the condition that led to the nodule developing. If lung cancer is the root cause, then the patient may not display any symptoms other than a cough or coughing blood. Our pulmonary care doctor is able to detect a lung nodule via a chest x- ray or a computed tomography scan (CT scan).