Jaron Chong MD, Presenter: Nothing to Disclose

Shaza Alsharif MD, Abstract Co-Author: Nothing to Disclose

Sarkis Meterissian, Abstract Co-Author: Nothing to Disclose

Benoit Delphin Mesurolle MD, Abstract Co-Author: Nothing to Disclose

The purpose of this study was to evaluate the longitudinal follow-up patterns of core-biopsy diagnosed fibroadenomas and to conduct a cost-effectiveness utility analysis of post-biopsy ultrasound examinations.

Core-biopsy diagnosed fibroadenomas from ultrasound and stereotactic guided breast biopsies performed over a 6-year period (2008-2013) were identified. The complete clinical records of these patients was retrospectively analyzed to assess for the occurence of lesion upgrade or transformation to a fibroepithelial or phylloides lesion. Analysis of follow-up practice behaviour was also performed to characterize the burden of post-biopsy follow-up examinations.

Of 754 core-biopsy diagnosed fibroadenomas, 125 (16.6%) demonstrated atypical characteristics involving hypercellularity, microcalcifications or adenosis, with 6 (0.8%) final diagnosis upgrade events identified. 5 typical fibroadenomas were upgraded to a benign phylloides and 1 atypical fibroadenoma was upgraded to a benign phylloides. For these lesions, the interval between fibroadenoma core-biopsy and full-excision diagnosis of a phylloides tumor was 39 - 479 days (mean 221.3 days). The final excisional size of upgraded lesions ranged from 1.5 - 4.6 cm (mean 2.9cm) and was not significantly different from non-upgraded lesions. Increase in size from previous was noted on 3 of the 6 lesions. Of the 748 non-upgraded lesions, 458 underwent a follow-up breast examination, and over 399 (53.3%) underwent a subsequent follow-up ultrasound, with the number of follow-up ultrasounds ranging from 1 to 8 (mean 2.1 examinations; total 829 examinations). Cost analysis of these post-biopsy ultrasound examinations, incurred potential estimated total costs of $82,900.

Upgraded re-classification of a fibroadenoma to a phylloides tumor post core-biopsy was a rare event. When upgrades did occur, suspicion due to growth was clinically evident or had atypia initially warranting aggressive investigation. In our case series, not performing lesion follow-up post core-biopsy diagnosis of fibroadenoma would have resulted in 6 missed diagnosis upgrades to benign phylloides out of 754 biopsies. 

Long-term follow-up of core biopsy proven fibroadenomas yielded rare upgraded diagnoses or transformations. Further investigation into the role for limited follow-up guidelines post core-biopsy is warranted.

Chong, J, Alsharif, S, Meterissian, S, Mesurolle, B, Fibroadenoma Transformation and Upgrade to Phylloides Tumors Post Core-Biopsy: A Longitudinal Review of Fibroepithelial Spectrum Lesions.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14016244.html