Benign phyllodes tumour with intraductal papillary growth of the breast in a young woman

A 24-year-old woman noted a mass in her left breast and visited a local hospital. The mass was ∼2.5 cm in size upon imaging and considered to be a benign tumour, so she was monitored. Six months later, the mass enlarged to >3 cm, showed redness in the skin and was painful. She took antibiotics for 1 week, and symptoms improved. She was referred to the Social Insurance Kurume Daiichi Hospital (Kurume, Japan). Ultrasonography revealed an intracystic tumour measuring ∼3.3×3.3×3.5 cm consisting of a solid papillary structure in a cystic lesion and with an inhomogeneous interior (figure 1). Dynamic MRI revealed an irregular-shaped solid portion, with enhancement within the tumour and haemorrhagic fluid in the lumen: malignancy was suspected. Local excisional biopsy was undertaken for diagnostic purposes and at the request of the patient. …