Fibroadenomas are benign, are considered to arise out of an “aberration of normal development” (ANDI). Available evidence points to a polygenic nature and thus, they are not considered to be neoplasms.
The cause of these lesions is unknown.
- there is no definite side predilection (isolated reports indicate a very small left sided predilection).
- occur more often in the upper outer quadrant of the breast.
- rarely, fibroadenomas are multiple (multiple fibroadenomas and especially recurrent tumors, have been reported very rarely and the majority of these cases have been part of familial syndromes, in non-Caucasians).Recurrent tumors may arise in the same quadrant of the breast (35% in one report).
- may involute in postmenopausal women, and coarse calcifications may develop.
- fibroadenomas may grow rapidly during pregnancy, during hormone replacement therapy, or during immunosuppression.
- in the immunosuppressed organ transplant setting, they are frequently multiple, bilateral and rapidly growing. The suspicion that Epstein-Barr virus infection may be a causative factor has remained unproven.
- possible role of oral contraceptives in the etiology is as yet unproven.
Diagnosis is by ‘triple assessment’(clinical examination, imaging & biopsy).
Natural history: Approximately 10% of fibroadenomas tend to disappear spontaneously each year, and most stop growing after they reach a size of 2-3 cm. Some studies indicate that the probability that a fibroadenoma would resolve after 5 years is approximately 50%, and the “lifetime” of a fibroadenoma is about 15 years. Among the 50% of fibroadenomas that do not regress spontaneously, about half may remain without change in size, and the remaining 25% may enlarge.
Risk of malignancy: Some studies have calculated the risk of breast cancer to be 1.3 to 2.1 times higher in women with fibroadenomas compared with the general population. Malignant transformations in the epithelial components of fibroadenomas are generally considered rare.
The incidence of a carcinoma evolving within a fibroadenoma is said to be in the region of 0.002% - 0.0125%. Risk in higher in a sub-set of these tumors histologically classified as “complex” fibroadenomas, in tumors with adjacent proliferative changes and in patients with proven breast cancer in a first degree relative.
Management: Surgical excision can be by
- the conventional ‘open’ wide excision – meaning, removal of the mass with a 1 cm rim of sorrounding normal tissue.
- by ultrasound-guided, vacuum-assisted percutaneous excision (a minimally invasive treatment).
There is general agreement that fibroadenomas can be diagnosed preoperatively with a high degree of confidence using the triple assessment and that some of the lesions thus diagnosed will spontaneously resolve, possibly obviating the need for surgical excision. There is, however, wide disagreement over the proportion of fibroadenomas that may resolve spontaneously and therefore the benefit that may be gained from an expectant policy.
There have been a fair number of trials of conservative management of fibroadenomas in the literature, reports indicating that many of them were satisfied with this approach.
One example of the indications and follow-up recommendations are as shown below.
- tumors <3 cms in size,
- those that are confidently diagnosed as ‘benign’ on triple assessment (including mammography for those >35 yrs), and
- in non-familial cases only.
If the tumors continued to grow during the follow-up they are excised. In women <35 years, Fibroadenomas that either don’t regress completely, or remain static by the age of 35, are excised. In women >35 yrs, shorter follow-ups of 6-12 months is proposed and if the tumors persist beyond this period are excised.
Conservative management of Fibroadenomas has come into the picture relatively recently and not all surgeons may have experience with it.
Therfore, at present,
- there seems to be a place for conservative management, and
- the preferred of management option for these tumors may depend upon a surgeon’s acceptance of this concept, experience with this modality and of course, the patient’s preferences.
MB BS, MS, FRCS(Edinburgh)