Core Needle Biopsy


Breast Cyst
Breast Abscess
Breast Cancer

Fibroadenoma – An Overview

Fibroadenoma is the most common type of breast lump in young women. Recent research has revealed that a fibroadenoma develops from a breast lobule. Park et al showed that fibroadenoma resembled the hyperplastic nodules commonly found in normal breasts. Fibroadenoma are hormonally dependent as they can lactate during pregnancy and regress after menopause. With this evidence some authors suggest that fibroadenoma are an aberration of normal development of the breast (concept of ANDI). This would explain why it is most common in women during the period of breast development (15 to 25 years old). Typically a fibroadenoma is between 1 to 3 cm in diameter, firm, well circumscribed and mobile. Overall, clinical diagnosis is only 60% accurate as it is difficult to differentiate from other benign lumps.

The investigation of choice is an ultrasound scan which will show a well defined solid nodule. Mammogram is not commonly performed as the breasts of young women are mostly firm and hence appear opaque on the mammogram (radiodense). Moreover, most clinicians would advise against mammography in women below 35 years old to avoid radiating the developing breast. A fine needle aspiration (FNA) can be performed to obtain a cytological diagnosis. Likewise a core needle biopsy can be performed to obtain a tissue diagnosis. Cant et al studied the role of FNA in 321 women with a clinical diagnosis of fibroadenoma. All women subsequently had excision of their lumps for histological diagnosis. They found a sensitivity of FNA for fibroadenoma of 86% (I.e. FNA diagnosed the majority of fibroadenoma) but a low specificity of 76% (i.e. FNA has difficulty in differentiating fibroadenoma from fibroadenosis). More importantly, they found that FNA correctly diagnosed all 4 patients with breast cancer.

Is it necessary to excise?

Some authors have questioned the traditional approach of excising all fibroadenoma. They argued that with ultrasound scan and FNA, fibroadenoma can be diagnosed accurately and no malignancy missed. Studies on their natural history have shown that about 30% of fibroadenoma can regress when followed up for 2 years. The chance of malignant transformation in a fibroadenoma is also rare with less than 200 reported cases. These authors proposed that fibroadenoma can be treated with the following criteria/conditions:

1.  Woman < 30 years old when the chance of malignancy is low

2.  Routine use of FNA to exclude malignancy

3.  Fibroadenoma < 4 cm. rare variants such as phylloides tumour or juvenile fibroadenoma are usually >           4cm diameter and are usually excised.

The proponents for a surgical approach argue that excision allows for a complete cure and pathological examination of the lump. The patient can be psychologically reassured and no periodic long-term follow up is needed. However surgery can result in keloid scars in young women. (Table 2)

Mammogram, Mammotome, Radiation, Chemotherapy

Table 2  Conservatism vs. Excision on the Treatment of Fibroadenoma

Conservative Treatment


One third regressed

Complete cure

Low chance of malignant transformation

Full histological examination

No carcinoma missed by FNAC


Repeated investigations

Surgery involved

Long term follow up

Keloid scar in young women

In summary, a woman below 30 years old and with a fibroadenoma of less than 4cm diameter can be offered conservative treatment if the ultrasound scan and FNAC are both benign. However, for women who are not prepared for regular reviews and long term follow up, and who want confirmation of diagnosis, excision is the obvious approach.

It is of note that there exists a new and untried approach to the treatment of fibroadenoma, which is the use of minimally invasive surgery of the breast with automated core biopsy devices such as the mammotome. This approach can obtain multiple core biopsies of a small breast lump via a cosmetically small (< 5mm diameter) skin incision.

Ultrasound Scan, FNA, Malignancy

Phylloides Tumour - What Is It?

Phylloides tumour is a rare variant of fibroadenoma. It is difficult to differentiate from a fibroadenoma clinically and radiologically. It grows more rapidly than a fibroadenoma. On cross-section, it often appears softer than a fibroadenoma, has a brownish colour and a leaf like pattern. Grossly the tumour appears well defined but is prone to recurrence if enucleated i.e. excised without a rim of normal tissue. This is due to the invasion of adjacent breast tissue by the tumour. If suspected of gross appearance at time of surgery, a phylloides tumour should be excised with a 1cm margin to prevent local recurrence. Frozen section if available is helpful. Some sources advise performing a wide excision if the margin of an excised phylloides tumour is not clear. 5% of phylliodes tumour are malignant and commonly metastasize to the lungs . Such behaviour is sometimes difficult to predict from the histopathology. The treatment of malignant phylloides tumour is usually mastectomy. Unfortunately, they respond poorly to radiation or chemotherapy.


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