Less than five percent of all of the tumors that originate in the lungs are benign, according to John Minna, M.D., Professor of Internal Medicine and Pharmacology at the University of Texas Southwestern Medical Center in “Harrison’s Principles of Internal Medicine.” Some of the tumors can interfere with the airway. People may spit up blood, cough or develop a lung infection, but some people with a benign lung tumor may not have any symptoms at all.
Pulmonary Hamartoma
A hamartoma is a growth of tissues and cells that are in the right place, but they are not in the right mixture. Pulmonary hamartomas have normal lung tissue and cells, but they are disorganized. People with this type of benign lung tumor are usually approximately 60 years old, writes Dr. Minna in “Harrison’s Principles of Internal Medicine.” Men have pulmonary hamartomas more often than women. Pulmonary hamartomas do not usually cause symptoms.
Bronchial Carcinoid
This type of benign lung tumor is a neuroendocrine tumor, which means it has a relationship between the nervous system and the endocrine system that causes it to release hormones into the bloodstream when it is stimulated by the nervous system. For example, it may release the adrenocorticotropic hormone, or ACTH. Too much of this hormone can lead to Cushing syndrome in which people have high levels of cortisol. The tumor may release the growth-hormone-releasing factor, causing an excess of growth hormone in the body, which can lead to acromegaly. People with acromegaly have a large jaw, feet and hands. The kidneys, liver, spleen, heart and lungs also increase in size. Bronchial carcinoids may also release the gastrin hormone, which can lead to Zollinger-Ellison syndrome characterized by peptic ulcers and diarrhea.
Approximately 50 percent of people with bronchial carcinoids do not have any symptoms of the carcinoid, but some may have difficulty breathing or they may cough and wheeze. Many times, physicians mistake these symptoms for asthma, per Waun Ki Hong, M.D. in “The Merck Manual for Healthcare Professionals.” Others may have chest pain, spit up blood or have reoccurring pneumonia.
Bronchial Adenoma
An adenoma is a benign tumor that resembles a gland or has structures that look like a gland. In “Harrison’s Principles of Internal Medicine,” Dr. Minna writes that half of all benign lung tumors are bronchial adenomas. This type of tumor grows slowly. The average age for somebody with this tumor is 45 years old. Most of the time, people have symptoms for years. For example, they may have a chronic cough and develop abscesses and infections. The bronchial adenoma may interfere with the airway and cause part of the lung to collapse. This tumor has a lot of blood vessels, which can cause some people to spit up blood.
References
- “Harrison’s Principles of Internal Medicine”; Anthony Fauci, M.D., Dennis Kasper, M.D., Dan Longo, M.D. et al.; 2008
- The Merck Manual for Healthcare Professionals: Bronchial Carcinoid
