Ultrasound diagnosis of fibroadenoma - is biopsy always necessary?

To review the ultrasound characteristics of fibroadenoma and the necessity to biopsy all fibroadenomas in the under 25 years age group.

The details of all patients under 25 years of age who attended a large district general hospital in the UK between 1995 and 2005 with a clinical diagnosis of fibroadenoma and subsequently, underwent a breast biopsy were obtained. The report of the targeted ultrasound for these patients was reviewed and this was correlated with the histopathology report (n=447). If there was a significant discrepancy between the ultrasound and the pathology report, the ultrasound images were reviewed.

Out of 447 patients 357 had an ultrasound diagnosis of fibroadenoma. This was histologically proven in 281 (78.8%) cases. In 75 (21.5%) of these patients the final histology was either another benign pathology or normal. One patient (0.3%) had an invasive carcinoma.

The majority of patients in the 25 years and under age group have benign breast pathology, most commonly fibroadenoma. Modern ultrasound is a reliable technique to diagnose fibroadenoma in the hands of experienced breast radiologists. Therefore, in this age group, it is proposed that a palpable lump that has the ultrasound characteristics entirely consistent with a fibroadenoma need not be biopsied unless there is overriding clinical concern. The patients should be reassured, discharged, and advised to return for further evaluation only if they detect a change in the palpable abnormality.