Benign Lung Tumors - Causes, Types, Symptoms, and Treatment

Introduction:

Benign tumors are an abnormal formation of tissue that is not dangerous. It does not spread to other parts of the body. A tumor that occurs in the lungs or airways leads to the lungs. Early detection of tumors helps prevent many complications. Benign lung tumors are common, as one of the hundred computed tomography scans reports lung masses or tumors. Among these, 99 % are benign conditions.

What Are the Characteristics of Benign Lung Tumors?

The benign features of the tumor are:

1. The tumors are not cancerous and do not spread to other body parts.

2. It grows slowly or shrinks and may not be growing.

3. These tumors usually do not need to be removed.

4. Usually not life-threatening.

5. Benign tumors have a tendency to expand and push against nearby tissue but do not invade or replace other tissues.

What Are the Different Causes of Benign Lung Tumors?

The proper cause of the benign tumor is unknown. But they often occur as a result of these problems:

• Inflammation From Infections:

  • Tuberculosis.
  • Lung abscess (a cavity filled with pus as a result of bacterial infection on the tissues of the lungs).
  • Fungal infection (histoplasmosis, aspergillosis, coccidioidomycosis, cryptococcosis).
  • Round pneumonia (a type of pneumonia commonly seen in children present with typical round opacities).

• Inflammation From Non-infectious Causes:
• Sarcoidosis - This refers to the collection of small tiny inflammatory cells in any part of the body. This disease mostly occurs in the lungs, eyes, lymph nodes, and the skin.
• Wegener’s Granulomatosis- Refers to the inflammation of blood vessels. The abnormal activity of the immune system results in the construction of blood vessels and the formation of granulomas.
• Rheumatoid Arthritis- This refers to the chronic inflammatory condition that affects joints of the hands and feet particularly. In this condition, the body’s immune system acts against their own tissues of joints.
• Congenital disabilities or birth defects such as lung cysts or other lung malformations.

What Are the Types of Benign Lung Tumors?

The tumors are generally more than three centimeters in diameter. If the tumor is less than three centimeters, it is called a nodule. There are several types of lung tumors, and these include-

1. Hamartomas: Hamartomas are firm marble-like tumors that are formed from the tissues lining the lungs and also from the tissues of fat and cartilages. These are most commonly seen in the periphery of the lungs. It is found to be more common in males than females, between the ages of 50 and 70. Hamartomas are usually confined within a limited area and do not press against nearby tissue. It is one of the most common types of benign lung tumor and the third most common solitary lung nodule. In chest radiographs, these benign tumors appear like a coin-like round mass growth.

2. Bronchial Adenomas: These tumors arise from the ducts of the windpipe or large airways and from the mucous glands of the lungs. These kinds of tumors contribute to half of all benign lung tumors. For example, mucous gland adenoma is a true benign bronchial adenoma tumor.

3. Papillomas: Papillomas grow in the bronchial tubes, emerging out from the surface area where they are attached. It is a less common type of benign lung tumor. It is classified into three types, and they include -

• Squamous: Squamous papillomas can occur both in children and adults. Papillomas are formed as a result of infection by the human papillomavirus (HPV), the viruses which are also responsible for causing warts and certain sexually transmitted diseases.

• Glandular: These kinds of papillomas arise from the larger airways and are less common than squamous papillomas. It occurs as one nodule which is centrally located; the cause is unknown.

• Mixed Squamous and Glandular: In this type, the papillomas consist of a mix of both squamous and glandular papilloma tissue. Due to the presence of squamous cells, these papillomas have a tendency to turn cancerous as squamous cells can change over time. Only a few cases have been recorded.

4. Other Benign Lung Tumors: Other rarely occurring benign lung tumors are fibromas, lipomas, chondromas, and neurofibromas which are tissue masses formed from the tissues of fatty or connective tissues.

What Are the Symptoms of Benign Lung Tumors?

The most common symptoms of benign lung tumors include:

• Shortness of breath.

• Wheezing.

• Persistent cough.

• Hemoptysis (coughing up blood).

• Fever, particularly if pneumonia is present.

• Recurrent respiratory infections, such as pneumonia.

• Atelectasis - A part of the lung has collapsed.

How Are Benign Lung Tumors Diagnosed?

Diagnosis of lung tumors is based on a proper history, assessment of risk factors, and physical examination.

Imaging Studies-

1. Chest X-Ray:

Lung tumors can be viewed on the chest X-ray after it reaches the size of about one centimeter in diameter. The findings of the chest X-ray alone cannot confirm that the tumor is benign or malignant. As the report suggests, about 25 % of pulmonary cancers are missed on chest X-rays.

Findings of benign lung tumors on imaging studies-

1. Benign tumors are usually small and less than three centimeters.

2. These tumors have a regular shape and smooth borders.

3. The proliferating or doubling time is usually slow.

4. These tumors have calcifications that are speckled, diffuse, or popcorn-like appearance.

5. Absence of an increase in the size of the lymph nodes.

6. No evidence of spreading to other regions of the body.

2. Computed Tomography (CT) Scan-

Computed tomography of the chest is carried out to get detailed images or to further clarify the findings obtained from a chest X-ray. In some cases, a benign tumor can only be determined when this scan is performed.

Biopsy-

• A biopsy can be done either through an aspiration method (fine needle aspiration biopsy) or removal of sample tissue through a surgical procedure (open biopsy) or during bronchoscopy.
• If a tumor is present near the large airways, it can be easily seen in bronchoscopy. An endobronchial biopsy can be done through the airways during this procedure.

Other tests are performed at times based on the underlying disease and conditions, such as blood tests, tuberculin skin tests for checking tuberculosis, single-photon emission computed tomography (SPECT), positron emission tomography (PET), magnetic resonance imaging (MRI) in rare cases.

How Are Benign Lung Tumors Treated?

• The treatment of a benign lung tumor is based on the symptoms and the particular type of tumor present.

• The benign tumors are removed during the biopsy procedure if the tumor is small and under the following situations-

1. If the patient is a smoker and the tumor is slightly larger in size.
2. If the nodule or tumor is growing or increasing in size.
3. If present with symptoms or any discomfort.
4. A scan suggests the nodule or tumor may be cancerous.

• A procedure called video-assisted thoracoscopic surgery is performed to gain faster recovery for surgical removal of benign lung tumors. It is carried out by making a few incisions on the chest wall to gain access to the lungs. Then, specialized fine instruments are used to remove part or entire lobe of the lungs.

Conclusion:

Benign lung tumors represent various different groups of tumors. Similar to malignant tumors, these benign tumors increase in size, cause symptoms, and recur after removal but do not spread to other body regions, differentiating them from malignancies. Fortunately, most tumors are harmless and can be left untreated.