Fibroadenoma

Fibroadenomas have previously been regarded as benign neoplasms, but should now be considered as an aberration of normal development. The peak incidence occurs in the third decade. An increasing number of newly developed fibroademonas are being detected in the fifth and sixth decade, probably related to increased use of HRT and mammographic screening.

Fibroadenomas develop from a lobule in the breast rather than from a single cell, and demonstrate high levels of estrogen and sulfates as well as of enzymes responsible for the formation of estrogen (sulfatase and aromatase), suggesting hormone dependency. Clonal analysis has demonstrated that fibroadenomas are polyclonal lesions. The natural history of fibroadenomas is now better understood, with 72% resolving over a period of 7 years.

There is no increased risk of breast cancer in patients with fibroadenomas, apart from a small pathological subgroup (i.e., those with complex fibroadenomas - cysts greater than 3 mm in diameter, sclerosing adenosis, epithelial calcifications or papillary change; relative risk [RR] of 3.1 for breast cancer). Fibroadenomas can undergo vascular infarction during pregnancy and lactation and in their later stages can undergo calcification.

Multiple Fibroadenomas
In a small percentage of patients, multiple fibroadenomas are detected either by clinical examination or screening mammography. The sensible approach in these patients is to investigate each lesion on its merit and perform core biopsies to confirm their benign nature. Excision biopsy is advised for any lesion where the diagnosis is uncertain.

Juvenile and Giant Fibroadenomas
Classically, juvenile fibroadenomas are rare and occur in adolescence. They are characterized by a rapidly growing lesion that usually attains a size greater than 5 cm in diameter causing distortion and asymmetry of the breast. These lesions require surgical excision for cosmetic reasons. Giant fibroadenomas attain a similar size but are usually found in the breasts of pregnant or lactating women and increase under the hormonal environment of these physiological conditions. They frequently diminish in size after the hormonal influences recede. If they remain large, they may be excised for cosmetic reasons. Neither of these lesions have any malignant potential.

Symptoms

Patients present with a discrete lump that may in rare cases be associated with tenderness. Occasionally patients may present with multiple discrete lumps at initial presentation.

Signs

Clinical examination usually demonstrates a well-circumscribed, mobile, firm, discrete breast lump.

Investigations