Rapidly progressive multifocal phyllodes tumour of the breast: A case report and review of the literature.

INTRODUCTION: Malignant transformation of a phyllodes tumour is a rare form of breast cancer, accounting for just 0.5% of all breast cancer cases.(1) PRESENTATION OF CASE: We report a case of a 49 year old female with rapidly progressive, multifocal disease. She initially presented with two giant fibroadenomas which were excised. She represented eight months post surgery with two new lesions in the same breast, one suspicious, one suggestive of fibroadenoma. Biopsy was borderline. Surgery was therefore scheduled for wide local excision. At localisation two weeks later, at least eight lesions were seen on ultrasound scan. Three were removed as histology was at this point unknown to conserve the breast. Histology revealed intermediate grade DCIS, benign Phyllodes and borderline/malignant phyllodes. She was scheduled for mastectomy and immediate Strattice reconstruction. An MRI was performed pre-operatively to ascertain extent of disease. Two weeks post localisation, 13 lesions were identified. The right breast was entirely unaffected. Surgery interval was three weeks and final histology revealed 18 lesions, ranging from fibroadenoma through to borderline/malignant phyllodes with an incidental papilloma. DISCUSSION: This is the first report of such rapid progression of disease, with 16 new lesions, of varied histology, developing in just an eight week period.
CONCLUSION: This case highlights the difficulty of forming a clear diagnostic and therapeutic pathway in this highly variable disease. Arguments for over and under treating these patients remain but those with any borderline/malignant potential have to be removed as recurrence is both common and aggressive, with a clear surgical margin the only proven protective factor.