Yazan Masannat, Consultant Oncoplastic Breast Surgeon, Aberdeen Royal Infirmary

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Fibroadenomas are one of the most common forms of benign breast disease. Whilst they may occur at any age, they are most common in premenopausal women. In the majority of cases they present as a solitary breast lump, which is well circumscribed and mobile. Modern diagnostic techniques have superseded the need for excision biopsy of suspected fibroadenomas however some patients require surgery..

Demographics

 

The prevalence of fibroadenomas is difficult to quantify but has been estimated between 7% and 13%.  The most common age for development is in the second and third decades of life. Risk factors for the development of fibroadenoma include higher socioeconomic class and the presence of dark skin.

 

Signs

 

The commonest presentation is to the symptomatic breast clinic with a breast lump in the younger age group while in the older population they may be found incidentally on screening. They present as a solitary, smooth, rubbery mobile breast lump which is non tender. Normally the range of diameter is 1-3cm, if a fibroadenoma grows to greater than 5cm this is referred to as giant fibroadenoma.

 

Pathology

 

Fibroadenomas are part of ANDI (Aberration of Normal Development and Involution). It usually arises from the terminal ductal-lobular Unit and is composed of epithelial and connective tissue components. They are influenced  by hormonal variation.

Between the ages of 15 and 25, under the influence of cyclic exposure to sex hormones, the breast develops lobules in addition to the ducts which develop during puberty. Commonly hyperplastic lobules develop at this stage in development. Fibroadenoma occur in a single breast lobule, histologically they are identical to hyperplastic lobules. They contain both epithelial and stromal cells. Like normal breast lobules fibroadenoma are responsive to hormones, demonstrating growth when exposed to sex hormones and involution following menopause.

 

Giant Fibroadenoma

Approximately 4% of all fibroadenomas are greater than 5cm, referred to as giant fibroadenomas. They develop in the adult breast, during pregnancy or lactation in most cases. They are referred to as juvenile giant fibroadenomas when developing in the adolescent.

 

Multiple fibroadenoma

An estimated 1 in 10 patients with a single fibroadenoma will have further present in their breasts. Unlike in solitary lesions, there is some evidence to suggest that there may be a familiar component to the development of multiple fibroadenoma.

 

Investigations

 

The appearance of a fibroadenoma on ultrasound is a smoothly contoured lesion with weak internal echoes and uniform distribution. Mammography may be useful in the diagnosis of fibroadenoma in older patients. Classically the appearance of fibroadenoma on mammography is of a mass well demarcated from the surrounding tissues exhibiting a surrounding area of radiolucency known as the halo sign. Fibroadenomas may also contain areas of calcification.

 

Fine needle aspirate (FNA) of fibroadenoma may demonstrate benign epithelial cells and myoepithelial cells both of which are normally contained within breast parenchyma. The addition of fine needle aspirate to ultrasound in the investigation of fibroadenoma significantly increases both the diagnostic accuracy and the accuracy in exclusion of malignancy.

 

Management

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The development of a fibroadenoma is thought to occur over a 12 month period. More than half will stay the same size after diagnosis, about a third will decrease in size and less that 10% will increase in size. Excision is recommended for the ones that are increasing in size, or if on diagnosis they are more than 4cm, or if the diagnosis is in doubt on triple assessment.

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The following video shows excision of a recurrent fibroadenoma

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References

 

• Alexis M Willett, Michael J Michell, Martin J R Lee Best practice diagnostic guidelines for patients presenting with breast symptoms, November 2010

• Brinton LA, Vessey MP, Flavel R, Yeates D. Risk factors for benign breast disease. Am J Epidemiol. 1981 Mar;113(3):203-14

• Cant PJ, Madden MV, Coleman MG, Dent DM. Non-operative management of breast masses diagnosed as fibroadenoma. Br J Surg. 1995 Jun;82(6):792-4.

• Carty NJ, Carter C, Rubin C, Ravichandran D, Royle GT, Taylor I. Management of fibroadenoma of the breast. Ann R Coll Surg Engl. 1995 Mar;77(2):127-30

• Catherine N. Chinyama (2013). Benign Breast Diseases: Radiology - Pathology - Risk Assessment. -: Springer Science & Business Media.

• Cole-Beuglet C, Soriano RZ, Kurtz AB, Goldberg BB. Fibroadenoma of the breast: sonomammography correlated with pathology in 122 patients. AJR Am J Roentgenol. 1983 Feb;140(2):369-75

• Dixon, JM (2013). Breast Surgery: A Companion to Specialist Surgical Practice, Saunders Limited, 5th edition.

• Dixon JM, Dobie V, Lamb J, Walsh JS, Chetty U. Assessment of the acceptability of conservative management of fibroadenoma of the breast. Br J Surg. 1996 Feb;83(2):264-5

• Greenberg R, Skornick Y, Kaplan O. Management of breast fibroadenomas. J Gen Intern Med. 1998 Sep;13(9):640-5. Review.

• Houssami N, Cheung MN, Dixon JM. Fibroadenoma of the breast. Med J Aust. 2001 Feb 19;174(4):185-8. Review

• Hughes LE, Mansel RE, Webster DJ. Aberrations of normal development and involution (ANDI): a new perspective on pathogenesis and nomenclature of benign breast disorders. Lancet. 1987 Dec 5;2(8571):1316-9

• Wilkinson S, Anderson TJ, Rifkind E, Chetty U, Forrest AP. Fibroadenoma of the breast: a follow-up of conservative management. Br J Surg. 1989 Apr;76(4):390-1.

• Williamson ME, Lyons K, Hughes LE. Multiple fibroadenomas of the breast: a problem of uncertain incidence and management. Ann R Coll Surg Engl. 1993 May;75(3):161-3

•  Yu H, Rohan TE, Cook MG, Howe GR, Miller AB. Risk factors for fibroadenoma: a case-control study in Australia. Am J Epidemiol. 1992 Feb 1;135(3):247-58.

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