What are the other Names for this Condition? (Also known as/Symptoms)

• Paraganglioma of Lung

What is Pulmonary Paraganglioma? (Definition/Background Information)

• Pulmonary Paraganglioma is a very rare and benign tumor of lung that generally affects men and women. The tumors are observed to mostly develop in the lung parenchyma (lung tissue) or mediastinum (chest cavity)
• These neuroendocrine tumors can occur either sporadically or as part of multiple endocrine neoplasia 2 (MEN 2) syndromes; MEN 2 is a syndrome causing endocrine gland tumors. The exact cause of Pulmonary Paraganglioma is unknown
• Some paragangliomas are known to metastasize and spread to the lungs from other parts of the body (known as secondary Pulmonary Paraganglioma), while some may form in the lungs and spread to other regions of the body (known as primary Pulmonary Paraganglioma)
• Most lung paragangliomas may not present any significant signs and symptoms and hence may go undetected. The tumors are usually detected incidentally, while the individual is being examined for other health conditions
• Pulmonary Paragangliomas may present chest pain, cough, and fever that may lead to complications such as pneumonia and obstruction of the airways. Metastatic tumors may affect the function of several body organs
• The healthcare provider may undertake treatment (surgical removal of the tumor) in case it causes worrisome signs and symptoms. Treating the underlying MEN type 2 disorder (if present) is also undertaken
• The prognosis of Pulmonary Paraganglioma is typically good since most tumors are benign tumors. Although, in some cases, the prognosis may be linked to the underlying MEN 2 disorder and its severity

Who gets Pulmonary Paraganglioma? (Age and Sex Distribution)

• Pulmonary Paraganglioma is a highly infrequent lung tumor that is usually observed in adults
  • When it occurs randomly and not as part of MEN type 2 syndrome, it is frequently found in men in the 30-50 years age group
  • When it occurs as part of MEN type 2 syndrome, the condition is commonly seen in women at an earlier age (less than 30 years)
• Paraganglioma of Lung is observed worldwide and there is no racial or ethnic group predilection

What are the Risk Factors for Pulmonary Paraganglioma? (Predisposing Factors)

• Currently, no risk factors have been identified for sporadic Pulmonary Paraganglioma
• Some cases are known to be associated with multiple endocrine neoplasia 2 (MEN 2) syndromes. MEN type 2 is an inherited genetic disorder involving tumors of the endocrine glands

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Pulmonary Paraganglioma? (Etiology)

• The cause of development of Pulmonary Paraganglioma is generally unknown
• Some cases are known to be linked to multiple endocrine neoplasia type 2 disorder, for unknown reasons
• Research is currently being undertaken to identify the relevant causal factors

What are the Signs and Symptoms of Pulmonary Paraganglioma?

The signs and symptoms of Pulmonary Paraganglioma may include the following:

• A vast majority of tumors are benign and asymptomatic
• However, paragangliomas may arise in some other part of the body and metastasize to the lungs
• The tumors can occur in the lung parenchyma or mediastinum; very rarely the bronchial airways may be involved (endobronchial tumors)
• The tumors are normally slow-growing; some of them can be more aggressive in their growth pattern
• They are generally solitary in nature; multiple tumors may be observed very infrequently
• Endobronchial tumors can cause obstructive symptoms including chest pain, cough, and blood in sputum
• Some tumors can produce hormones such as norepinephrine. In such individuals, increased blood pressure may be noticed; some tumors may release other hormones too
• Signs and symptoms of the underlying MEN type 2 syndrome, if present

How is Pulmonary Paraganglioma Diagnosed?

There are a variety of tests the healthcare provider may employ to diagnose Pulmonary Paraganglioma, This may include:

• Physical examination and complete medical history screening: During the physical exam, the healthcare provider may listen to the lung  with a stethoscope, to detect the presence of any abnormal lung sounds
• Imaging studies that may include a chest x-ray, MRI scan or CT scan of the lungs
• Arterial blood gases
• Blood test to detect elevated levels of hormones such as epinephrine
• Lung function test
• Sputum cytology: This procedure involves the collection of mucus (sputum), coughed-up by a patient, which is then examined in a laboratory by a pathologist
• Tests and exams to establish MEN type 2 disorder

A tissue biopsy refers to a medical procedure that involves the removal of cells or tissues, which are then examined by a pathologist. This can help establish a definitive diagnosis. The different biopsy procedures may include: 

• Bronchoscopy: During bronchoscopy, a special medical instrument called a bronchoscope is inserted through the nose and into the lungs to collect small tissue samples. These samples are then examined by a pathologist, after the tissues are processed, in an anatomic pathology laboratory
• Thoracoscopy: During thoracoscopy, a surgical scalpel is used to make very tiny incisions into the chest wall. A medical instrument called a thoracoscope is then inserted into the chest, in order to examine and remove tissue from the chest wall, which are then examined further
• Thoracotomy: Thoracotomy is a surgical invasive procedure with special medical instruments to open-up the chest. This allows a physician to remove tissue from the chest wall or the surrounding lymph nodes of the lungs. A pathologist will then examine these samples under a microscope after processing the tissue in a laboratory
• Fine needle aspiration biopsy (FNAB): During fine needle aspiration biopsy, a device called a cannula is used to extract tissue or fluid from the lungs, or surrounding lymph nodes. These are then examined in an anatomic pathology laboratory, in order to determine any signs of abnormality. Nevertheless, FNAB is not a preferred method for the biopsy of lung tumors
• Autofluorescence bronchoscopy: It is a bronchoscopic procedure in which a bronchoscope is inserted through the nose and into the lungs and measure light from abnormal precancerous tissue. Samples are collected for further examination by a pathologist

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Pulmonary Paraganglioma?

The complications of Pulmonary Paraganglioma may include the following:

• Metastasis: It is common to find metastasis to lung from other parts of the body, than a primary Pulmonary Paraganglioma. The tumors that metastasize are called malignant paragangliomas
• Metastasis to regional lymph nodes has also been observed
• Obstruction of the airways in case of a large-sized tumor
• Pneumonia
• Severe chest pain
• Large tumors may also compress the heart and impede its functioning
• Tremendous psychological stress in the individual, since it can mimic lung cancer
• Additional complications that occur due to the underlying MEN type 2 disorder

How is Pulmonary Paraganglioma Treated?

The treatment of Pulmonary Paraganglioma may involve the following:

• The treatment of choice is complete surgical excision, which can result in a cure
• In case of malignant tumors, radiation therapy may be provided
• Some studies have shown that chemotherapy may be helpful in some cases
• Undertaking appropriate treatment of underlying MEN type 2 syndrome
• Follow-up care with regular screening and check-ups are important and encouraged

How can Pulmonary Paraganglioma be Prevented?

Currently, there are no known methods to prevent the development of Pulmonary Paraganglioma.

• In case of multiple endocrine neoplasia type 2 syndrome, genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counselling will help assess risks, before planning for a child

What is the Prognosis of Pulmonary Paraganglioma? (Outcomes/Resolutions)

• The prognosis for sporadic Pulmonary Paraganglioma is generally good with appropriate treatment, since it is a benign tumor
• The prognosis of metastatic tumors depend upon the stage of the tumor and overall health of the individual, besides other factors
• However, the outcome for Paraganglioma of Lung in the backdrop of multiple endocrine neoplasia type 2 depends upon the severity of the signs and symptoms of the underlying disorder

Additional and Relevant Useful Information for Pulmonary Paraganglioma:

Multiple endocrine neoplasia (MEN) Type 2 is a syndrome involving tumors of the endocrine glands. It is an inherited genetic condition.