WHAT ARE HAMARTOMAS?
Hamartomas are benign lesions that present as mature but architecturally incomplete tissues on a localization that should not contain such a tissue. Though many authors put them in the tumor like categories, due to the fact that they are a developmental malformation, they can be also a real neoplastic lesion due to the fact that their origins are somatic mutations that led to chromosomal aberrations. The term hamartoma was used for the first time by Arigoni et al in 1971.
WHAT IS THE OCCURRENCE RATE OF HAMARTHOMAS?
Hamartomas are a benign tumors and their incidence is between 0.7 – 4.8%. Their incidence is increasing due to the screening procedures for breast cancer. So these lesions present an incidental finding in most cases. Incidence is increasing, these tumors are still very rare and publications are describing individual cases of small series of cases.
A few cases have been registered in men, these changes are more common in middle aged women, while in pediatric population this is very rare.
HOW ARE THEY MANIFESTED?
Clinically they are presented as a slow growing, hard tumor mass in the breast that is oval or round, movable, clearly demarcated, smooth in surface. They can be presented in different dimensions from small non palpable masses to huge masses over 10cm in diameter.
WHAT ARE THEY MADE OF?
Histologically it is a benign lesion made out of epithelium, fibrous and fatty tissue in different proportions. As these tissues are the elements of the breast these tumors are sometimes referred to as breast inside the breast. Depending from the overpowering component they can be lipo-fibro-adenomas, fibro-adeno-lipomas or adeno-lipomas. Myoid hamartomas are rare and they are a form of fatty tissue with smooth muscle tissue. These tumors can contain micro calcifications and ossifications in them.
WHY DO THEY APPEAR?
Ethiopathogenesis is not known, but as previously mentioned, it is believed that there is dysgenesis in question rather than a real tumor. A possible contributing factor are female hormones, due to the fact that some of these tumors present with estrogen and progesterone receptors. Smooth muscle component in myoid hamartomas is probably from the vessel walls origin, mammillary origin or myoepithelial cell of the breast origin or un differentiated stromal cells. It is also possible that mechanisms or appearance and metaplasia of stromal cells into muscle cells due to the immunohistochemistry finding that hamartomas have C+ and CMA+, as well as expression of desmin and vimentin.
Hamartomas are a common finding in Cowden syndrome, which is a rare autosomal dominant syndrome happening because of a mutation of PTEN tumor suppressor gene. It is characterized by appearance of multiple hamartomas of skin, mucosa, brain, breast, thyroid and gastrointestinal tract, abnormalities in the central nervous system, and increased risk of breast cancer and thyroid comparing to the general population.
ARE THEY DANGEROUS?
Cases have been described where there is an invasive carcinoma inside the hamathoma. Malignant transformation is possible considering presence of epithelial component inside the tumor and over to cellular atypia that leads to carcinoma development. Differential diagnosis can be fibro adenomas, but those never have fatty tissue in them.
HOW ARE THEY DISCOVERED?
Ultrasound describes these changes a solid, clearly demarcated, avascular, non-homogenous, hypo and hyper echogenic structures depending on the content of glandular, fibrous and fatty tissue. Mammogram presents as oval or round lesions, non-homogenous with radio opaque and transparent areas depending on the build, that are clearly demarcated by a capsule. If they have a large quantity of fibrous tissue, then they are more homogenous and difficult to differentiate from fibroadenoma and if they have more fatty tissue then they are more likely to look like lipomas. On MRI these changes present as heterogeneous, and after contrast administration they show benign type I curvature.
HOW TO TREAT THEM?
Therapy of choice is surgical removal of the entire lesion. Enucleation of these tumors is relatively easy due to the presence of capsule or pseudo capsule. Relapse is rare after complete excision.
PLEASE HAVE THINGS YOU ARE IN THE VID!
This site is informative-educational. Our goal is to provide helpful information on symptoms and treatment of the disease to people with breast disorders.
If you feel you have any of these symptoms, please contact your doctor. DO NOT use these therapies yourself without prior consultation with a doctor!
1. Amir RA, Sheikh SS. Breast hamartoma: A report of 14 cases of an under-recognized and under-reported entity. Int J Surg Case Rep. 2016; 22:1-4.
2. Bhatia M, Ravikumar R, Maurya VK, Rai R. “Breast within a breast” sign: Mammary hamartoma. Med J Armed Forces India. 2015 Oct; 71(4): 377-9.
3. Presazzi A, Di Giulio G, Calliada F. Breast hamartoma: ultrasound, elastosonographic, and mammographic features. Mini pictorial essay. J Ultrasound. 2015 Jul 26; 18(4): 373-7.
4. Sevim Y, Kocaay AF, Eker T, Celasin H, Karabork A, Erden E, Genc V. Breast hamartoma: a clinicopathologic analysis of 27 cases and a literature review. Clinics (Sao Paulo). 2014 Aug; 69(8):515-23.
5. Gupta SS, Singh O, Hastir A, Arora G, Sabharwal G, Mishra H. Breast hamartoma with intrathoracic extension in a 13-year-old boy. J Cancer Res Ther. 2010 Jan-Mar; 6(1): 86-8.