Table of ContentsView AllTable of ContentsAbnormal GrowthSymptomsCommon LocationsCan It Spread?What Causes Hamartomas?Diagnosis/TreatmentWhat to Ask AboutFrequently Asked Questions
Table of ContentsView All
View All
Table of Contents
Abnormal Growth
Symptoms
Common Locations
Can It Spread?
What Causes Hamartomas?
Diagnosis/Treatment
What to Ask About
Frequently Asked Questions
A hamartoma is abenign tumorthat may occur in the lungs, heart, skin, brain, breast, or other regions.They are made up of abnormal but not cancerous cells similar to the cells that make up the tissue where they originate.
Hamartomas can look similar to cancer on imaging studies, and for this reason, can be very frightening.In some regions of the body, they may not cause any symptoms. They can sometimes shrink on their own, but in other cases, they can cause complications.
They may also occur as part of syndromes that predispose people to cancer in several different organs.Often, there are no symptoms associated with a hamartoma, and they are found incidentally when a test is ordered for another reason, but when they cause symptoms, it is often related to the location where they occur.
Nephron / Wikimedia Commons / CC BY 3.0
Hamartoma vs. Healthy Tissue
A hamartoma is a benign (non-cancerous) tumor that is made up of “normal” tissues that are found in the region in which they grow. For example, a lung (pulmonary) hamartoma is a growth of non-cancerous tissues including fat, connective tissue, and cartilage that is found in the regions of the lungs.
The difference between hamartomas and normal tissue is that hamartomas grow in a disorganized mass.Most hamartomas grow slowly, at a rate similar to normal tissues. They are more common in men than in women. While some are hereditary, nobody knows for sure what causes many of these growths to occur.
Hamartoma Symptoms
One of the most common “symptoms” is fear, as these tumors can look very much like cancer when found, especially on imaging tests.
Common Hamartoma Locations
Hamartomas can occur almost anywhere in the body. Some of the more common areas include:
Lung (Pulmonary) Hamartomas
Hamartomas are the third most common cause of solitary pulmonary nodules in the lung. They’re often discovered accidentally when chest imaging is done for some other reason.
With the increased use ofCT screening for lung cancerin people at risk, it’s likely that more people will be diagnosed with hamartomas in the future.
If you have recently had CT screening and your healthcare provider is considering that you may have a benign tumor such as a hamartoma, ask about what happens when you have a nodule on screening and the chances that it’s cancer.
Hamartomas can be difficult to distinguish from cancers but do have some characteristics that set them apart. A description of “popcorn calcification"—meaning images that look like popcorn on a CT scan—is almost diagnostic.
Calcifications (deposits of calcium that appear white on X-ray studies) are common. Cavitation, a central area of tissue breakdown seen on X-rays, is uncommon. Most of these tumors are less than 4 centimeters (2 inches) in diameter.
In addition to hamartomas, there are several other types of benignlung nodules.
Can Hamartomas Spread?
It’s also important to note that people with Cowden’s disease (a syndrome in which people have multiple hamartomas) are more likely to develop cancers, especially of the breast and thyroid.So even though hamartomas are benign, your healthcare provider may want to do a thorough examination and possibly imaging studies to rule out the presence of cancer.
Nobody is sure what causes hamartomas, although they are more common in people with some genetic syndromes such as Cowden’s disease.
Hamartomas and Cowden Syndrome
Hamartomas often occur as part of the hereditary syndrome known as Cowden’s disease. An autosomal dominant genetic mutation most often causes Cowden’s disease, meaning that if either your father or mother inherits the mutation, the chance that you will have it as well is around 50%.
In addition to multiple hamartomas (related to a form of PTEN gene mutation,) people with this syndrome often develop cancers of the breast, thyroid, and uterus, often beginning in their 30s and 40s.
Syndromes such as Cowden’s syndrome help explain why your healthcare provider should have a thorough history of any cancers (or other conditions) whichrun in your family. In syndromes such as these, not all people will have one type of cancer, but a combination of certain types of cancer is likely.
Diagnosis and Treatment
The diagnosis of a hamartoma will depend on where it occurs. Since they can appear similar to a malignant tumor (cancer) on imaging, a biopsy is often needed to confirm the diagnosis.
Treatment options for a hamartoma will depend largely on the location of the tumor and whether or not it is causing symptoms. If hamartomas are not causing symptoms, your healthcare provider may recommend that the tumor be left alone and observed over time.
Surgery
Procedures, when needed for pulmonary hamartomas includewedge resection(removal of the tumor and a wedge-shaped section of tissue surrounding the tumor), lobectomy (removal of one of the lobes of a lung), orpneumonectomy(removal of a lung).
Questions to Ask Your Healthcare Provider
If you’ve been diagnosed with a hamartoma, make sure you understand your diagnosis and whether treatment is needed. Start with these questions:
If you’re considering genetic testing for cancer, it’s helpful to have genetic counseling first.
A Word From Verywell
Hamartomas are benign (noncancerous) tumors that will not spread to other parts of your body. Sometimes they are left alone, but if they are causing symptoms due to their location, or if the diagnosis is uncertain, surgery to remove the tumor may be recommended.
For some people, a hamartoma may be a sign of a gene mutation that can increase the risk of some cancers such as breast cancer and thyroid cancer. It’s important to talk to your healthcare provider about any specialized testing you should have if this is the case. Talking with a genetic counselor may also be recommended.
Frequently Asked QuestionsYes, if they’re causing symptoms or your healthcare provider isn’t 100% sure it’s a benign tumor. Otherwise, they can be left alone.Hamartomas can be surgically removed if they’re causing problems. While you await surgery, you may feel better if your symptoms are treated. (This varies depending on the location and symptoms.) Otherwise, no treatment is generally needed.Rarely, hamartomas can become malignant (cancerous).
Yes, if they’re causing symptoms or your healthcare provider isn’t 100% sure it’s a benign tumor. Otherwise, they can be left alone.
Hamartomas can be surgically removed if they’re causing problems. While you await surgery, you may feel better if your symptoms are treated. (This varies depending on the location and symptoms.) Otherwise, no treatment is generally needed.
Rarely, hamartomas can become malignant (cancerous).
20 Sources
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Lu Z, Qian F, Chen S, Yu G.Pulmonary hamartoma resembling multiple metastases: A case report.Oncol Lett. 2014;7(6):1885–1888. doi:10.3892/ol.2014.2043
Gosein MA, Narinesingh D, Nixon CA, Goli SR, Maharaj P, Sinanan A.Multi-organ benign and malignant tumors: recognizing Cowden syndrome: a case report and review of the literature.BMC Res Notes. 2016;9:388. doi:10.1186/s13104-016-2195-z
National Institutes of Health, U.S. National Library of Medicine: MedlinePlus.Pulmonary hamartoma.
Ladeira I, Neves S, Almeida J, Parente B, Couceiro A, Moura Sá J.Diffuse vascular hamartoma with malignant behavior.Respir Med Case Rep. 2015;15:125–127. doi:10.1016/j.rmcr.2015.05.007
Kishore M, Gupta P, Preeti, Deepak D.Pulmonary Hamartoma Mimicking Malignancy: A Cytopathological Diagnosis.J Clin Diagn Res. 2016;10(11):ED06–ED07. doi:10.7860/JCDR/2016/22597.8844
Chen SS, Zhou H, Tong B, Yu LL, Fan SS, Xiao ZK.Endobronchial hamartoma mimicking malignant lung tumor contralateral endobronchial metastasis: A case report.Medicine (Baltimore). 2017;96(49):e9085. doi:10.1097/MD.0000000000009085
Tjarks BJ, Gardner JM, Riddle ND.Hamartomas of skin and soft tissue.Semin Diagn Pathol. 2019;36(1):48-61. doi:10.1053/j.semdp.2018.12.001
National Organization for Rare Disorders.Hypothalamic Hamartoma.
Gao CM, Ma YQ, Yu C, Xie N, Ma Y.A case report of giant hamartoma of both kidneys with spontaneous rupture and hemorrhage in a pregnant woman: A case report.Biomed Rep. 2019;11(2):59–62. doi:10.3892/br.2019.1223
Illuminati G, Prezioso G, Pizzardi G, et al.Splenic hamartoma associated with abdominal discomfort and pain: Case report.International Journal of Surgery Open. 2018;13:1-5. doi:10.1016/j.ijso.2018.07.002
Bhatia M, Ravikumar R, Maurya VK, Rai R.“Breast within a breast” sign: Mammary hamartoma.Med J Armed Forces India. 2015;71(4):377–379. doi:10.1016/j.mjafi.2015.06.009
De Luca G, Griffo S, Rocco G.Popcorn in the lung.Journal of Thoracic Oncology. 2014;9(9):1418. doi:10.1097/JTO.0000000000000178
Loverdos K, Fotiadis A, Kontogianni C, Iliopoulou M, Gaga M.Lung nodules: A comprehensive review on current approach and management.Ann Thorac Med. 2019;14(4):226–238. doi:10.4103/atm.ATM_110_19
National Institutes of Health, U.S. National Library of Medicine: StatPearls.Cowden disease (multiple hamartoma syndrome).
Gammon A, Jasperson K, Champine M.Genetic basis of Cowden syndrome and its implications for clinical practice and risk management.Appl Clin Genet. 2016;9:83–92. doi:10.2147/TACG.S41947
Schenkel R, Altfillisch C, Chung J, Verma A, Balters M.Malignant Degeneration of Biopsy-Proven Hamartoma to Chondrosarcoma.Cureus. 2020;12(12):e12150. Published 2020 Dec 18. doi:10.7759/cureus.12150
Elsayed H, Abdel Hady SM, Elbastawisy SE.Is resection necessary in biopsy-proven asymptomatic pulmonary hamartomas?.Interact Cardiovasc Thorac Surg. 2015;21(6):773-776. doi:10.1093/icvts/ivv266
Esme H, Duran FM, Unlu Y.Surgical treatment and outcome of pulmonary hamartoma: a retrospective study of 10-year experience.Indian J Thorac Cardiovasc Surg. 2019;35(1):31-35. doi:10.1007/s12055-018-0728-x
Edey AJ, Hansell DM.Incidentally detected small pulmonary nodules on CT.Clin Radiol. 2009;64(9):872-884. doi:10.1016/j.crad.2009.03.006Farooq A, Walker LJ, Bowling J, Audisio RA.Cowden syndrome.Cancer Treat Rev. 2010;36(8):577-583. doi:10.1016/j.ctrv.2010.04.002Mester J, Charis E.PTEN hamartoma tumor syndrome.Handb Clin Neurol. 2015;132:129-137. doi:10.1016/B978-0-444-62702-5.00009-3National Institutes of Health, U.S. National Library of Medicine: MedlinePlus.Cowden syndrome.Saqi A, Shaham D, Scognamiglio T, et al.Incidence and cytological features of pulmonary hamartomas indeterminate on CT scan.Cytopathology. 2008;19(3):185-191. doi:10.1111/j.1365-2303.2007.00439.x
Edey AJ, Hansell DM.Incidentally detected small pulmonary nodules on CT.Clin Radiol. 2009;64(9):872-884. doi:10.1016/j.crad.2009.03.006
Farooq A, Walker LJ, Bowling J, Audisio RA.Cowden syndrome.Cancer Treat Rev. 2010;36(8):577-583. doi:10.1016/j.ctrv.2010.04.002
Mester J, Charis E.PTEN hamartoma tumor syndrome.Handb Clin Neurol. 2015;132:129-137. doi:10.1016/B978-0-444-62702-5.00009-3
National Institutes of Health, U.S. National Library of Medicine: MedlinePlus.Cowden syndrome.
Saqi A, Shaham D, Scognamiglio T, et al.Incidence and cytological features of pulmonary hamartomas indeterminate on CT scan.Cytopathology. 2008;19(3):185-191. doi:10.1111/j.1365-2303.2007.00439.x
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